ASTM E1360-05(2019)

Standard Practice for Specifying Color by Using the Optical Society of America Uniform Color Scales System

SIGNIFICANCE AND USE
5.1 Notational systems that specify and identify colors have proved to be very useful. This practice describes how to assign an OSA-UCS notation to a color specimen. This notation gives its position within the color space determined by the Optical Society of America Committee on Uniform Color Scales to represent the closest possible approximation to a color space in which equal distances equate to equal visually perceived differences. The cuboctahedral sampling fills the color space with a more closely spaced set of samples than would a cubic lattice or samples placed on polar coordinates.
SCOPE
1.1 This practice provides a means for specifying the colors of objects in terms of the Optical Society of America Uniform Color Scales. Both computational and visual methods are included. The practice is limited to opaque objects, such as painted surfaces, viewed in daylight by an observer having normal color vision.  
1.2 This practice does not cover the preparation of specimens. If the preparation of specimens is required in conjunction with this practice, a mutually agreed upon procedure shall be established.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2019
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.07 - Color Order Systems

Relations

• Replaces: ASTM E1360-05(2015) - Standard Practice for Specifying Color by Using the Optical Society of America Uniform Color Scales System
• Effective Date: 01-Nov-2019
• Refers: ASTM E1164-23 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 01-Nov-2023
• Refers: ASTM E308-17 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-May-2017
• Refers: ASTM E308-15 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-Apr-2015
• Refers: ASTM D1535-14 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Nov-2014
• Refers: ASTM E284-13b - Standard Terminology of Appearance
• Effective Date: 01-Nov-2013
• Refers: ASTM E284-13a - Standard Terminology of Appearance
• Effective Date: 01-Jun-2013
• Refers: ASTM D1535-13 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Jan-2013
• Refers: ASTM E284-13 - Standard Terminology of Appearance
• Effective Date: 01-Jan-2013
• Refers: ASTM D1535-12a - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 15-Jul-2012
• Refers: ASTM E1164-12e1 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 01-Jul-2012
• Refers: ASTM E1164-12 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 01-Jul-2012
• Refers: ASTM E308-12 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-Jul-2012
• Refers: ASTM E284-12 - Standard Terminology of Appearance
• Effective Date: 01-Jul-2012
• Refers: ASTM D1535-12 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Feb-2012

Overview

ASTM E1360-05(2019): Standard Practice for Specifying Color by Using the Optical Society of America Uniform Color Scales (OSA-UCS) System provides a comprehensive methodology for defining and identifying the color of opaque objects. Developed by ASTM International, this standard equips professionals with a uniform notation system to describe colors as accurately as possible, reflecting equal steps in visually perceived color differences. ASTM E1360 applies specifically to painted surfaces and similar opaque objects, emphasizing the observer's standard daylight vision. Both computational (instrumental) and visual assessment approaches are included, enhancing versatility and practical relevance.

Key Topics

• OSA-UCS Notation System: The core of this standard is the Optical Society of America Uniform Color Scales. Color is specified by three coordinates (L, j, g), representing lightness and opponent-color axes for yellowness-blueness and greenness-redness.
• Visual and Computational Methods: ASTM E1360 details both visual comparison against physical OSA-UCS color samples and calculation from colorimetric data, ensuring flexible application across laboratory and production settings.
• Color Order and Equal Visual Spacing: The OSA-UCS system is structured so that equal distances within the color space correspond to equal perceived color differences. The cuboctahedral arrangement leads to a denser, more uniform sampling than traditional cubic or polar coordinate systems.
• Controlled Viewing Conditions: Only opaque specimens observed in daylight by individuals with normal color vision are covered. The standard defines preferred backgrounds, lighting, and reference samples to support repeatability.
• Importance of Standardization: ASTM E1360 supports international harmonization by aligning with globally recognized principles for standard development, as outlined by the World Trade Organization’s Technical Barriers to Trade (TBT) Committee.

Applications

Implementing ASTM E1360 is valuable across industries requiring accurate, reproducible color specification for materials and products:

• Paints & Coatings: Assure consistency in color formulation and quality control by specifying product batches using the OSA-UCS system.
• Plastics, Textiles, and Decorative Surfaces: Objectively communicate color requirements to suppliers and clients, reducing ambiguity and minimizing costly mismatches.
• Industrial Quality Assurance: Use computational or visual OSA-UCS methods to check color conformity during production, facilitating international supply and compliance.
• Laboratory Color Science: Provide a standardized reference for research in color measurement, appearance, and human visual perception studies.

Related Standards

For broader or complementary color specification and measurement needs, the following ASTM standards and international practices are closely related and often referenced with ASTM E1360:

• ASTM D1535: Standard Practice for Specifying Color by the Munsell System - widely used for soil, art materials, and educational purposes.
• ASTM D1729: Standard Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials.
• ASTM E284: Terminology of Appearance - offers definitions and concepts relating to color and gloss.
• ASTM E308: Practice for Computing the Colors of Objects by Using the CIE System – a primary standard for instrumental color measurement.
• ASTM E1164: Practice for Obtaining Spectrometric Data for Object-Color Evaluation – foundational for laboratory instrumentation.

Practical Value

Adopting ASTM E1360-05(2019) enables organizations to:

• Achieve precise, objective, and repeatable color communication in contracts, specifications, and quality assurance processes.
• Bridge the gap between visual assessment and instrumental measurement of color, ensuring alignment among laboratories, suppliers, and end-users.
• Enhance global market access by adhering to internationally recognized measurement principles and standardized notations.

For up-to-date versions and full procedural details, consult the official ASTM documentation at www.astm.org.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1360 − 05 (Reapproved 2019)
Standard Practice for
Specifying Color by Using the Optical Society of America
Uniform Color Scales System
This standard is issued under the fixed designation E1360; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
TheOpticalSocietyofAmericaUniformColorScales(OSA-UCS)weredevelopedbyacommittee
oftheOpticalSocietyofAmericaintheyearsbetween1947and1974inanefforttoprovideasystem
andasetofsamplesthatrepresenttheclosestpossibleapproximationtoequalvisualspacing (1). The
system is defined by a set of equations derived from the results of visual scaling experiments and
related to the 1964 CIE system. The OSA sample set consisted of 558 atlas samples that fell at the
lattice points of a rhombohedral close-packed arrangement within the color space defined by the
equations. The unit in this spacing is a cuboctahedron, each color being surrounded by twelve
equidistant nearest neighbors. See Fig. 1 and Fig. 2. Fig. 3 shows a OSA-UCS lightness plane plotted
on the CIE 1964 chromaticity diagram. The OSA-UCS system is described in Appendix X1.
The system is independent of the OSA-UCS atlas samples, and other groups of samples could be
chosenwithinthedefinedcolorspace;however,forthevisualdeterminationofcolorsdescribedinthis
standard, the OSA set of samples is used.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice provides a means for specifying the colors
D1535Practice for Specifying Color by the Munsell System
of objects in terms of the Optical Society ofAmerica Uniform
D1729Practice for Visual Appraisal of Colors and Color
Color Scales. Both computational and visual methods are
Differences of Diffusely-Illuminated Opaque Materials
included. The practice is limited to opaque objects, such as
E284Terminology of Appearance
painted surfaces, viewed in daylight by an observer having
E308PracticeforComputingtheColorsofObjectsbyUsing
normal color vision.
the CIE System
1.2 This practice does not cover the preparation of speci-
E1164PracticeforObtainingSpectrometricDataforObject-
mens. If the preparation of specimens is required in conjunc-
Color Evaluation
tion with this practice, a mutually agreed upon procedure shall
be established. 3. Terminology
3.1 Definitions of Terms Specific to This Standard:
1.3 This international standard was developed in accor-
3.1.1 chromaticness, n—an attribute of a visual sensation
dance with internationally recognized principles on standard-
combining hue and chroma; the visual correlate of the colori-
ization established in the Decision on Principles for the
metric quantity chomaticity.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
3.1.2 hue, n—the attribute of color perception by means of
Barriers to Trade (TBT) Committee.
which an object is judged to be red, yellow, green, blue, or
intermediate between some adjacent pair of these. In the
OSA-UCS system each hue is denoted by its angle within a
360° circle beginning in the yellow direction on the right hand
This practice is under the jurisdiction ofASTM Committee E12 on Color and
AppearanceandisthedirectresponsibilityofSubcommitteeE12.07onColorOrder
Systems.
Current edition approved Nov. 1, 2019. Published November 2019. Originally
approved in 1990. Last previous edition approved in 2015 as E1360–05 (2015). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/E1360-05R19. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
The boldface numbers in parentheses refer to a list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this practice. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1360 − 05 (2019)
NOTE 1—Cuboctahedron showing location of L, j, and g axes through
its center and the locations and L, j, g coordinates of the center point and
its12nearestneighbors.ThelatticeoftheOSA-UCSsystemisderivedby
extending this unit in all directions to the extremes of color space. In this
NOTE 1—CIE 1964 (x , y )-chromaticity diagram showing chroma-
drawing horizontal nearest-neighbor planes are emphasized with heavy 10 10
ticitypoints(j,g)ofcolorsofOSAColorSystemforlightnesslevelL=0.
lines.FromBillmeyer,F.W.,Jr.,“SurveyofColorOrderSystems,” Color
The chromaticity point N is that of the nominal gray (D ) in the system.
Research and Application, Vol 12, (2). Copyright 1987, John Wiley & 65
From Wyszecki, G., and Stiles, W. S., Color Science, 2nd ed., (3).
Sons.
Copyright 1982, John Wiley & Sons.
FIG. 1 Cuboctahedron Showing Axes and Horizontal Planes
FIG. 3 OSA L = O Plane on the CIE 1964 Chromaticity Diagram
redness are used throughout this practice for convenience. However, this
does not imply that the j and g axes indicate the locations of the
corresponding unitary hues: The+j axis closely approximates the direc-
tion toward unitary yellow; but the+g axis divides the green and blue
regions, the−j axis divides the blue and purple regions, and the−g axis
locates pinks and magentas. It is probably best to think of j and g as
abstract symbols unassociated with color names (4).
3.1.4 OSA-UCS samples, n—the Optical Society of Ameri-
ca’s physical exemplification of the OSA-UCS color system,
which consisted of 558 samples displayed in a face-centered
lattice in three-dimensional space such that each interior
samplehas12nearestneighborsatequalintervalsfromit.This
configuration is sometimes referred to as a cuboctahedral or
rhombohedral lattice.
NOTE 1—Cuboctahedron of Fig. 1 showing a typical vertical plane ()
and a typical oblique plane (.) containing nearest-neighbor colors.
3.2 Definitions:
From Billmeyer, F. W., Jr., “Survey of Color Order Systems,” Color
3.2.1 The definitions in Practice D1535 and Terminology
Research and Application, Vol 12, (2). Copyright 1987, John Wiley &
E284 are applicable to this practice.
Sons.
FIG. 2 Cuboctahedron Showing Vertical and Oblique Planes
4. Summary of Practice
4.1 Computation Method—CIE 1964 tristimulus values for
sideofthehuecircleandproceedingcounterclockwisethrough
standard illuminant D and the 1964 supplementary (10°)
the greens, blues, and reds to return to the yellow hue, 360, on
standard observer are obtained from spectrophotometric or
the+j axis.
colorimetric measurements. See Practice E308 and Practice
3.1.3 OSA-UCS color system, n—Optical Society of
E1164. Transformation equations (5) from CIE 1964 tristimu-
America Uniform Color Scales color order system based on
lus values to OSA-UCS notations are given in Section 7, and
equality of visual spacing, which uses the lightness scale 6L
the OSA-UCS notations and CIE specifications of the OSA
and the opponent-color scales 6j(yellowness-blueness) and 6
atlas samples are given in Table 1.
g(greenness-redness).Acolor in the OSA-UCS system may be
4.2 Visual Method—Observers must have normal color
describedbyitsL,j,gnotationorbyitslightness,L;hueangle,
vision. Specimens should be viewed on an essentially nonse-
h , and chroma, c , designation.
OSA OSA
lectivegraybackgroundof30%luminousreflectance,equiva-
NOTE 1—The conventional terms yellowness, greenness, blueness, and lent to the OSA-UCS notationL=0,j=0,g=0, abbreviated
E1360 − 05 (2019)
TABLE 1 CIE Specification for OSA-UCS Notations
OSA Lattice Coordinates CIE Specifications OSA Lattice Coordinates CIE Specifications
L jg Y x y L jg Y x y
10 10 10 10 10 10
A: Full-Step Colors A: Full-Step Colors
−7 −3 −1 3.22 0.2588 0.2169 0 −6 10.29 0.4236 0.2940
−3 1 3.24 0.2152 0.2251 0 −4 10.83 0.3875 0.3053
0 −2 11.25 0.3511 0.3176
−1 −1 3.54 0.3113 0.2841 0 0 11.53 0.3139 0.3309
−1 1 3.59 0.2569 0.3002 0 2 11.61 0.2756 0.3455
0 4 11.45 0.2357 0.3617
1 −1 3.79 0.3783 0.3571
1 1 3.92 0.3147 0.3858 2 −8 9.49 0.5132 0.3159
2 −6 10.27 0.4751 0.3304
−6 −4 −2 4.85 0.2656 0.2044 2 −4 11.00 0.4363 0.3461
−4 0 4.89 0.2304 0.2101 2 −2 11.62 0.3968 0.3631
−4 2 4.88 0.1960 0.2164 2 0 12.04 0.3564 0.3816
2 2 12.18 0.3145 0.4023
−2 −4 5.05 0.3508 0.2471 2 4 11.97 0.2699 0.4262
−2 −2 5.22 0.3090 0.2565
−2 0 5.32 0.2665 0.2670 4 −8 9.06 0.5677 0.3432
−2 2 5.32 0.2239 0.2783 4 −6 9.97 0.5289 0.3627
4 −4 10.89 0.4883 0.3837
0 −6 4.85 0.4574 0.2841 4 −2 11.70 0.4466 0.4063
0 −4 5.24 0.4103 0.2981 4 0 12.29 0.4038 0.4310
0 −2 5.56 0.3626 0.3136 4 2 12.52 0.3592 0.4590
0 0 5.75 0.3139 0.3309 4 4 12.29 0.3110 0.4927
0 2 5.78 0.2632 0.3505
−3 −5 −1 13.44 0.2529 0.2238
2 −6 5.00 0.5240 0.3260 −5 1 13.48 0.2276 0.2287
2 −4 5.24 0.4774 0.3475 −5 3 13.45 0.2025 0.2339
2 −2 5.73 0.4249 0.3710
2 0 6.06 0.3709 0.3974 −3 −5 13.71 0.3372 0.2488
2 2 6.13 0.3139 0.4283 −3 −3 14.01 0.3088 0.2552
−3 −1 14.21 0.2802 0.2621
−5 −5 −1 6.97 0.2402 0.1997 −3 1 14.30 0.2515 0.2694
−5 1 6.99 0.2114 0.2044 −3 3 14.27 0.2224 0.2772
−5 3 6.96 0.1829 0.2095 −3 5 14.11 0.1930 0.2855
−3 −3 7.35 0.3069 0.2380 −1 −7 13.63 0.4063 0.2760
−3 −1 7.48 0.2723 0.2454 −1 −5 14.18 0.3754 0.2845
−3 1 7.52 0.2375 0.2533 −1 −3 14.64 0.3442 0.2937
−3 3 7.48 0.2027 0.2619 −1 −1 14.97 0.3126 0.3035
−1 1 15.14 0.2805 0.3140
−1 −5 7.42 0.3907 0.2740 −1 3 15.12 0.2476 0.3254
−1 −3 7.76 0.3516 0.2848 −1 5 14.89 0.2136 0.3377
−1 −1 8.00 0.3122 0.2965
−1 1 8.10 0.2720 0.3093 1 −9 12.89 0.4840 0.2981
−1 3 8.05 0.2305 0.3233 1 −7 13.71 0.4510 0.3089
1 −5 14.47 0.4176 0.3206
1 −7 6.95 0.4886 0.3026 1 −3 15.13 0.3839 0.3329
1 −5 7.53 0.4463 0.3171 1 −1 15.62 0.3496 0.3465
1 −3 8.04 0.4034 0.3329 1 1 15.90 0.3146 0.3609
1 −1 8.43 0.3596 0.3503 1 3 15.90 0.2782 0.3771
1 1 8.62 0.3147 0.3695 1 5 15.57 0.2397 0.3950
1 3 8.56 0.2670 0.3916
3 −9 12.53 0.5328 0.3256
3 −7 6.67 0.5505 0.3363 3 −7 13.53 0.4984 0.3399
3 −5 7.39 0.5063 0.3568 3 −5 14.50 0.4631 0.3553
3 −3 8.08 0.4604 0.3791 3 −3 15.37 0.4272 0.3717
3 −1 8.65 0.4132 0.4035 3 −1 16.05 0.3906 0.3893
3 1 8.96 0.3646 0.4307 3 1 16.46 0.3581 0.4087
3 3 8.89 0.3127 0.4631 3 3 16.49 0.3139 0.4305
3 5 16.03 0.2716 0.4561
−4 −4 −2 10.12 0.2758 0.2303
−4 0 10.20 0.2465 0.2362 5 −7 13.07 0.5465 0.3666
−4 2 10.21 0.2172 0.2425 5 −5 14.21 0.5104 0.3863
−4 4 10.13 0.1881 0.2492 5 −3 15.28 0.4732 0.4073
5 −1 16.17 0.4349 0.4299
−2 −4 10.45 0.3435 0.2642 5 1 16.72 0.3956 0.4548
−2 −2 10.72 0.3104 0.2726 5 3 16.78 0.3543 0.4837
−2 0 10.88 0.2770 0.2818 5 5 16.20 0.3092 0.5189
−2 2 10.91 0.2430 0.2914
−2 4 10.80 0.2084 0.3022
A: Full-Step Colors A: Full-Step Colors
−2 −6 0 17.31 0.2354 0.2183 1 −9 22.22 0.4541 0.3038
−6 2 17.31 0.2133 0.2225 1 −7 23.26 0.4268 0.3129
1 −5 24.20 0.3993 0.3226
E1360 − 05 (2019)
TABLE 1 Continued
OSA Lattice Coordinates CIE Specifications OSA Lattice Coordinates CIE Specifications
L jg Y x y L jg Y x y
10 10 10 10 10 10
−4 −2 18.10 0.2824 0.2474 1 −3 25.00 0.3714 0.3330
−4 0 18.23 0.2574 0.2531 1 −1 25.60 0.3432 0.3439
−4 2 18.26 0.2323 0.2591 1 1 25.96 0.3145 0.3555
−4 4 18.18 0.2071 0.2655 1 3 26.02 0.2849 0.3682
1 5 25.75 0.2541 0.3820
−2 −6 18.09 0.3658 0.2683
−2 −4 18.58 0.3386 0.2754 3 −9 21.97 0.4933 0.3291
−2 −2 18.96 0.3112 0.2829 3 −7 23.24 0.4646 0.3408
−2 0 19.19 0.2836 0.2910 3 −5 24.42 0.4357 0.3529
−2 2 19.27 0.2555 0.2995 3 −3 25.46 0.4063 0.3659
−2 4 19.16 0.2268 0.3086 3 −1 26.26 0.3764 0.3797
−2 6 18.87 0.1977 0.3182 3 1 26.77 0.3459 0.3946
3 3 26.89 0.3144 0.4109
0 −10 16.86 0.4609 0.2831 3 5 26.54 0.2812 0.4292
0 −8 17.71 0.4320 0.2914
0 −6 18.50 0.4029 0.3004 5 −9 21.43 0.5332 0.3520
0 −4 19.19 0.3736 0.3099 5 −7 22.89 0.5039 0.3664
0 −2 19.73 0.3440 0.3200 5 −5 24.31 0.4738 0.3815
0 0 20.10 0.3139 0.3309 5 −3 25.58 0.4432 0.3975
0 2 20.24 0.2831 0.3426 5 −1 26.60 0.4119 0.4146
0 4 20.12 0.2512 0.3553 5 1 27.26 0.3801 0.4330
0 6 19.71 0.2180 0.3692 5 3 27.45 0.3470 0.4535
5 5 27.01 0.3119 0.4773
2 −10 16.59 0.5043 0.3094
2 −8 17.65 0.4739 0.3203 7 −9 20.62 0.5724 0.3707
2 −6 18.66 0.4430 0.3320 7 −7 22.22 0.5431 0.3883
2 −4 19.57 0.4118 0.3443 7 −5 23.82 0.5127 0.4067
2 −2 20.32 0.3801 0.3577 7 −3 25.31 0.4814 0.4261
2 0 20.84 0.3479 0.3719 7 −1 26.55 0.4493 0.4468
2 2 21.07 0.3147 0.3874 7 1 27.38 0.4165 0.4694
2 4 20.93 0.2800 0.4046 7 3 27.63 0.3823 0.4948
2 6 20.35 0.2430 0.4243 7 5 27.09 0.3460 0.5249
4 −10 16.06 0.5486 0.3328 0 −6 0 26.50 0.2457 0.2349
4 −8 17.28 0.5175 0.3468 −6 2 26.52 0.2260 0.2391
4 −6 18.50 0.4853 0.3618
4 −4 19.64 0.4525 0.3775 −4 −2 27.49 0.2872 0.2598
4 −2 20.61 0.4192 0.3942 −4 0 27.68 0.2655 0.2652
4 0 21.32 0.3851 0.4124 −4 2 27.75 0.2437 0.2708
4 2 22.65 0.3500 0.4324 −4 4 27.68 0.2217 0.2767
4 4 21.49 0.3130 0.4551
−2 −4 28.12 0.3350 0.2835
6 −10 15.33 0.5915 0.3515 −2 −2 28.58 0.3118 0.2903
6 −8 18.65 0.5608 0.3691 −2 0 28.88 0.2883 0.2974
6 −6 18.02 0.5283 0.3877 −2 2 29.00 0.2644 0.3049
6 −4 19.36 0.4948 0.4072 −2 4 28.93 0.2401 0.3128
6 −2 20.55 0.4603 0.4282
6 0 21.45 0.4250 0.4508 0 −8 27.22 0.4130 0.2972
6 2 21.89 0.3885 0.4758 0 −6 28.14 0.3886 0.3050
6 4 21.91 0.3498 0.5046 0 −4 28.93 0.3640 0.3131
0 −2 29.57 0.3391 0.3218
−1 −5 −1 22.61 0.2618 0.2405 0 0 30.00 0.3138 0.3310
−5 1 22.69 0.2397 0.2454 0 2 30.20 0.2882 0.3406
−5 3 22.66 0.2176 0.2504 0 4 30.13 0.2617 0.3511
0 6 29.77 0.2345 0.3622
−3 −3 23.36 0.3099 0.2670
−3 −1 23.67 0.2856 0.2734 2 −8 27.35 0.4469 0.3230
−3 1 23.81 0.2612 0.2801 2 −6 28.50 0.4212 0.3327
−3 3 23.81 0.2364 0.2871 2 −4 29.52 0.3951 0.3429
−3 5 23.64 0.2113 0.2945 2 −2 30.36 0.3688 0.3537
2 0 30.95 0.3421 0.3652
−1 −7 22.97 0.3911 0.2841 2 2 31.25 0.3147 0.3775
−1 −5 23.68 0.3652 0.2917 2 4 31.19 0.2863 0.3909
−1 −3 24.27 0.3392 0.2996 2 6 30.73 0.2567 0.4056
−1 −1 24.70 0.3129 0.3081
−1 1 24.94 0.2861 0.3171 4 −8 27.16 0.4824 0.3475
−1 3 24.96 0.2588 0.3266
−1 5 24.74 0.2308 0.3369
A: Full-Step Colors A: Full-Step Colors
4 −6 28.55 0.4555 0.3594 9 −7 31.66 0.5387 0.4045
4 −4 29.81 0.4283 0.3719 9 −5 33.55 0.5126 0.4214
4 −2 30.87 0.4007 0.3852 9 −3 35.29 0.4858 0.4389
4 0 31.64 0.3726 0.3993 9 −1 36.76 0.4585 0.4578
4 2 32.05 0.3438 0.4146 9 1 37.79 0.4305 0.4780
E1360 − 05 (2019)
TABLE 1 Continued
OSA Lattice Coordinates CIE Specifications OSA Lattice Coordinates CIE Specifications
L jg Y x y L jg Y x y
10 10 10 10 10 10
4 4 32.01 0.3139 0.4315 9 3 38.24 0.4017 0.5003
4 6 31.42 0.2822 0.4506
2 −4 0 39.65 0.2716 0.2739
6 −8 26.63 0.5186 0.3697 −4 2 39.76 0.2523 0.2792
6 −6 28.24 0.4910 0.3841 −4 4 39.71 0.2329 0.2847
6 −4 29.74 0.4629 0.3992
6 −2 31.02 0.4343 0.4152 −2 −4 40.18 0.3324 0.2895
6 0 31.99 0.4052 0.4323 −2 −2 40.73 0.3121 0.2956
6 2 32.52 0.3753 0.4510 −2 0 41.10 0.2917 0.3020
6 4 32.49 0.3440 0.4720 −2 2 41.28 0.2709 0.3087
−2 4 41.24 0.2498 0.3156
8 −8 25.82 0.5544 0.3884
8 −6 27.59 0.5267 0.4057 0 −6 40.32 0.3783 0.3083
8 −4 29.29 0.4982 0.4237 0 −4 41.22 0.3571 0.3155
8 −2 30.78 0.4691 0.4427 0 −2 41.95 0.3396 0.3231
8 0 31.95 0.4392 0.4632 0 0 42.46 0.3138 0.3310
8 2 32.61 0.4086 0.4855 0 2 42.72 0.2918 0.3392
8 4 32.59 0.3765 0.5111 0 4 42.71 0.2692 0.3481
0 6 42.40 0.2460 0.3575
1 −5 1 32.01 0.2493 0.2580
−5 3 32.01 0.2298 0.2628 2 −6 40.90 0.4058 0.3329
2 −4 42.04 0.3834 0.3417
−3 −3 32.80 0.3107 0.2760 2 −2 42.97 0.3609 0.3508
−3 −1 33.14 0.2897 0.2818 2 0 43.64 0.3380 0.3604
−3 1 33.34 0.2686 0.2879 2 2 44.01 0.3147 0.3706
−3 3 33.36 0.2471 0.2041 2 4 44.03 0.2907 0.3816
−3 5 33.22 0.2254 0.3009 2 6 43.66 0.2658 0.3934
−1 −5 33.21 0.3577 0.2971 4 −6 41.17 0.4346 0.3570
−1 −3 33.86 0.3355 0.3041 4 −4 42.55 0.4114 0.3674
−1 −1 34.34 0.3131 0.3114 4 −2 43.70 0.3878 0.3783
−1 1 34.64 0.2903 0.3193 4 0 44.56 0.3639 0.3899
−1 3 34.71 0.2671 0.3274 4 2 45.05 0.3395 0.4023
−1 5 34.54 0.2434 0.3361 4 4 45.11 0.3143 0.4156
1 −7 32.90 0.4092 0.3158 6 −6 41.07 0.4646 0.3799
1 −5 33.91 0.3859 0.3240 6 −4 42.70 0.4406 0.3921
1 −3 34.77 0.3624 0.3328 6 −2 44.09 0.4162 0.4051
1 −1 35.42 0.3386 0.3420 6 0 45.14 0.3914 0.4188
1 1 35.83 0.3144 0.3517 6 2 45.76 0.3660 0.4335
1 3 35.96 0.2896 0.3620 6 4 45.86 0.3399 0.4496
1 5 35.76 0.2641 0.3731
8 −6 40.58 0.4952 0.4008
3 −9 31.73 0.4645 0.3310 8 −4 42.45 0.4706 0.4152
3 −7 33.10 0.4403 0.3406 8 −2 44.07 0.4456 0.4303
3 −5 34.35 0.4159 0.3507 8 0 45.32 0.4202 0.4464
3 −3 35.42 0.3912 0.3613 8 2 46.08 0.3941 0.4637
3 −1 36.26 0.3662 0.3726 8 4 46.23 0.3672 0.4829
3 1 36.81 0.3408 0.3845
3 3 37.01 0.3146 0.3973 10 −6 39.74 0.5257 0.4192
3 5 36.79 0.2873 0.4113 10 −4 41.81 0.5009 0.4359
10 −2 43.63 0.4756 0.4532
5 −7 32.96 0.4727 0.3643 10 0 45.09 0.4498 0.4719
5 −5 34.45 0.4474 0.3764 10 2 45.99 0.4233 0.4920
5 −3 35.76 0.4217 0.3891
5 −1 36.80 0.3957 0.4026 3 −3 −1 48.63 0.2926 0.2878
5 1 37.51 0.3691 0.4170 −3 1 48.89 0.2738 0.2933
5 3 37.78 0.3417 0.4327 −3 3 48.97 0.2549 0.2991
5 5 37.53 0.3132 0.4500
−1 −5 48.76 0.3524 0.3010
7 −7 32.47 0.5058 0.3858 −1 −3 49.55 0.3329 0.3073
7 −5 34.18 0.4798 0.4002 −1 −1 50.15 0.3131 0.3139
7 −3 35.72 0.4535 0.4153 −1 1 50.53 0.2932 0.3208
7 −1 36.98 0.4266 0.4313 −1 3 50.66 0.2729 0.3279
7 1 37.85 0.3992 0.4485
7 3 38.20 0.3709 0.4672 1 −5 49.74 0.3767 0.3251
7 5 37.92 0.3413 0.4887 1 −3 50.75 0.3562 0.3327
1 −1 51.52 0.3354 0.3406
A: Full-Step Colors A: Full-Step Colors
1 1 52.04 0.3143 0.3490 1 1 73.12 0.3143 0.3470
1 3 52.24 0.2929 0.3578
1 5 52.11 0.2709 0.3672 3 −1 73.96 0.3540 0.3635
3 1 74.76 0.3345 0.3722
3 −5 50.43 0.4024 0.3489
E1360 − 05 (2019)
TABLE 1 Continued
OSA Lattice Coordinates CIE Specifications OSA Lattice Coordinates CIE Specifications
L jg Y x y L jg Y x y
10 10 10 10 10 10
3 −3 51.68 0.3810 0.3580 5 −1 75.09 0.3762 0.3873
3 −1 52.66 0.3593 0.3675 5 1 76.07 0.3560 0.3974
3 1 53.32 0.3372 0.3776
3 3 53.61 0.3147 0.3881 B: Half-Step Colors
5 −5 50.77 0.4293 0.3722 −1.5 −1.5 −1.5 21.72 0.3121 0.2958
5 −3 52.27 0.4071 0.3828 −1.5 −0.5 21.86 0.2986 0.3000
5 −1 53.47 0.3846 0.3940 −1.5 0.5 21.96 0.2849 0.3043
5 1 54.30 0.3616 0.4059 −1.5 1.5 22.01 0.2712 0.3088
5 3 54.69 0.3381 0.4187
−0.5 −1.5 22.16 0.3275 0.3139
7 −5 50.71 0.4568 0.3945 −0.5 −0.5 22.34 0.3134 0.3188
7 −3 52.46 0.4343 0.4067 −0.5 0.5 22.46 0.2991 0.3238
7 −1 53.89 0.4110 0.4197 −0.5 1.5 22.53 0.2847 0.3290
7 1 54.90 0.3874 0.4337
7 3 55.39 0.3632 0.4487 0.5 −1.5 22.56 0.3436 0.3323
0.5 −0.5 22.77 0.3290 0.3378
9 −5 50.24 0.4851 0.4150 0.5 0.5 22.93 0.3143 0.3435
9 −3 52.21 0.4623 0.4290 0.5 1.5 23.02 0.2993 0.3495
9 −1 53.88 0.4385 0.4442
9 1 55.08 0.4143 0.4603 1.5 −1.5 22.91 0.3606 0.3507
9 3 55.68 0.3895 0.4777 1.5 −0.5 23.16 0.3455 0.3570
1.5 0.5 23.35 0.3302 0.3636
11 −3 51.56 0.4905 0.4492 1.5 1.5 23.46 0.3147 0.3704
11 −1 53.43 0.4665 0.4665
11 1 54.81 0.4420 0.4850 −1 −2 −1 24.19 0.2988 0.2908
−2 0 24.31 0.2861 0.2944
4 −2 −2 58.70 0.3124 0.2996 −2 1 24.38 0.2732 0.2983
−2 0 59.18 0.2942 0.3054
−2 2 59.43 0.2758 0.3114 −1 −2 24.51 0.3261 0.3038
−1 0 24.84 0.2995 0.3125
0 −4 59.39 0.3520 0.3173 −1 2 24.97 0.2726 0.3216
0 −2 60.26 0.3330 0.3240
0 0 60.89 0.3138 0.3310 0 −2 24.94 0.3414 0.3210
0 2 61.24 0.2944 0.3383 0 −1 25.17 0.3277 0.3259
0 4 61.29 0.2746 0.3460 0 0 25.35 0.3139 0.3309
0 1 25.47 0.2999 0.3362
2 −4 60.51 0.3750 0.3407 0 2 25.52 0.2858 0.3416
2 −2 61.60 0.3551 0.3486
2 0 62.40 0.3350 0.3569 1 −2 25.32 0.3574 0.3383
2 2 62.88 0.3146 0.3657 1 0 25.81 0.3290 0.3496
2 4 62.98 0.2937 0.3750 1 2 26.03 0.2998 0.3618
4 −4 61.30 0.3992 0.3638 2 −1 25.97 0.3595 0.3619
4 −2 62.63 0.3785 0.3732 2 0 26.22 0.3448 0.3683
4 0 63.63 0.3576 0.3830 2 1 26.39 0.3298 0.3751
4 2 64.24 0.3363 0.3934
4 4 64.41 0.3145 0.4044 −0.5 −2.5 −0.5 26.63 0.2870 0.2856
−2.5 0.5 26.72 0.2749 0.2891
6 −4 61.70 0.4244 0.3863
6 −2 63.28 0.4031 0.3972 −1.5 −1.5 27.03 0.3123 0.2986
6 0 64.50 0.3815 0.4086 −1.5 −0.5 27.19 0.2998 0.3026
6 2 65.26 0.3594 0.4208 −1.5 0.5 27.31 0.2873 0.3066
−1.5 1.5 27.37 0.2746 0.3107
8 −2 63.51 0.4286 0.4203
8 0 64.94 0.4084 0.4335 −0.5 −2.5 27.28 0.3393 0.3109
8 2 65.86 0.3838 0.4476 −0.5 −1.5 27.53 0.3264 0.3152
−0.5 −0.5 27.73 0.3134 0.3198
10 −2 63.27 0.4548 0.4420 −0.5 0.5 27.87 0.3003 0.3244
10 0 64.92 0.4322 0.4571 −0.5 1.5 27.96 0.2871 0.3292
−0.5 2.5 27.98 0.2738 0.3341
12 0 64.45 0.4584 0.4788
0.5 −2.5 27.70 0.3544 0.3273
5 −1 −1 70.76 0.3132 0.3158 0.5 −1.5 27.99 0.3411 0.3322
−1 1 71.24 0.2954 0.3220 0.5 −0.5 28.23 0.3277 0.3373
0.5 0.5 28.40 0.3143 0.3424
1 −1 72.49 0.3330 0.3396 0.5 1.5 28.51 0.3005 0.3479
0.5 2.5 28.54 0.2866 0.3536
B: Half Step Colors B: Half Step Colors
1.5 −1.5 28.40 0.3565 0.3492 0.5 1.5 32.44 0.3017 0.3464
1.5 −0.5 28.68 0.3427 0.3549 0.5 2.5 32.49 0.2890 0.3516
1.5 0.5 28.88 0.3288 0.3608
1.5 1.5 29.01 0.3147 0.3668 1.5 −1.5 32.34 0.3529 0.3478
1.5 −0.5 32.62 0.3403 0.3529
E1360 − 05 (2019)
TABLE 1 Continued
OSA Lattice Coordinates CIE Specifications OSA Lattice Coordinates CIE Specifications
L jg Y x y L jg Y x y
10 10 10 10 10 10
2.5 −0.5 29.06 0.3584 0.3725 1.5 0.5 32.83 0.3275 0.3582
2.5 0.5 29.30 0.3440 0.3791 1.5 1.5 32.97 0.3146 0.3637
0 −3 0 28.28 0.2765 0.2811 2.5 −0.5 33.03 0.3545 0.3691
2.5 0.5 33.28 0.3414 0.3750
−2 −1 28.75 0.3001 0.2938
−2 1 28.96 0.2764 0.3011 1 −2 −1 33.76 0.3011 0.2965
−2 0 33.90 0.2901 0.2999
−1 −2 29.09 0.3251 0.3059 −2 1 34.00 0.2791 0.3034
−1 −1 29.29 0.3130 0.3099
−1 0 29.45 0.3007 0.3141 −1 −2 34.13 0.3243 0.3077
−1 1 29.56 0.2884 0.3183 −1 0 34.52 0.3017 0.3154
−1 2 29.61 0.2759 0.3226 −1 2 34.70 0.2787 0.3233
0 −3 29.27 0.3516 0.3174 0 −2 34.65 0.3371 0.3225
0 −1 29.81 0.3265 0.3263 0 −1 34.91 0.3255 0.3267
0 1 30.13 0.3011 0.3358 0 0 35.11 0.3138 0.3310
0 3 30.20 0.2750 0.3458 0 1 35.25 0.3020 0.3354
0 2 35.33 0.2902 0.3398
1 −2 29.99 0.3537 0.3378
1 −1 30.28 0.3407 0.3428 1 −2 35.12 0.3505 0.3373
1 0 30.50 0.3277 0.3480 1 0 35.65 0.3266 0.3467
1 1 30.66 0.3145 0.3534 1 2 35.93 0.3021 0.3567
1 2 30.75 0.3011 0.3590
2 −1 35.87 0.3522 0.3573
2 −1 30.69 0.3555 0.3594 2 0 36.15 0.3398 0.3626
2 1 31.14 0.3285 0.3712 2 1 36.35 0.3273 0.3680
3 0 31.34 0.3571 0.3823 1.5 −1.5 −1.5 37.40 0.3126 0.3032
−1.5 −0.5 37.60 0.3018 0.3067
0.5 −2.5 −0.5 30.48 0.2891 0.2892 −1.5 0.5 37.74 0.2910 0.3102
−2.5 0.5 30.58 0.2779 0.2925 −1.5 1.5 37.83 0.2801 0.3138
−1.5 −1.5 30.89 0.3125 0.3012 −0.5 −1.5 38.00 0.3246 0.3176
−1.5 −0.5 31.06 0.3009 0.3049 −0.5 −0.5 38.22 0.3135 0.3215
−1.5 0.5 31.19 0.2894 0.3086 −0.5 0.5 38.39 0.3023 0.3254
−1.5 1.5 31.26 0.2777 0.3125 −0.5 1.5 38.50 0.2911 0.3295
−0.5 −2.5 31.17 0.3372 0.3125 0.5 −1.5 38.55 0.3370 0.3321
−0.5 −1.5 31.42 0.3253 0.3166 0.5 −0.5 38.81 0.3257 0.3363
−0.5 −0.5 31.62 0.3134 0.3207 0.5 0.5 39.01 0.3141 0.3408
−0.5 0.5 31.77 0.3014 0.3250 0.5 1.5 39.14 0.3026 0.3453
−0.5 1.5 31.87 0.2893 0.3294
−0.5 2.5 31.90 0.2771 0.3338 1.5 −1.5 39.05 0.3500 0.3466
1.5 −0.5 39.35 0.3383 0.3514
0.5 −2.5 31.62 0.3510 0.3276 1.5 0.5 39.58 0.3265 0.3563
0.5 −1.5 31.91 0.3388 0.3321 1.5 1.5 39.74 0.3146 0.3613
0.5 −0.5 32.14 0.3266 0.3367
0.5 0.5 32.32 0.3142 0.3416
as (0,0,0), and illuminated with natural or artificial daylight. 6. Apparatus (Visual Method)
OSA-UCS atlas samples are used as references in judging
6.1 OpticalSocietyofAmericaUniformColorScales,setof
test-specimen color. 4
558 samples.
6.2 Daylight Illuminating Equipment, as described in Prac-
5. Significance and Use
tice D1729 or equivalent. A source simulating CIE standard
5.1 Notational systems that specify and identify colors have
illuminant D is preferred.
provedtobeveryuseful.Thispracticedescribeshowtoassign
anOSA-UCSnotationtoacolorspecimen.Thisnotationgives
7. OSA-UCS Notations from CIE Coordinates
its position within the color space determined by the Optical
7.1 OSA-UCS Color Space—The three coordinates of the
Society of America Committee on Uniform Color Scales to
OSA Committee’s color space are (L, j, g) standing for
representtheclosestpossibleapproximationtoacolorspacein
lightness, yellowness-blueness, and greeness-redness, respec-
which equal distances equate to equal visually perceived
tively (see Note 1.) The initial j (from the French word jaune,
differences. The cuboctahedral sampling fills the color space
with a more closely spaced set of samples than would a cubic
lattice or samples placed on polar coordinates. These sets are no longer available commercially.
E1360 − 05 (2019)
for yellow) is used to avoid confusion with the CIE chroma- where h lies between 0 and 90° if g and j are both
OSA
ticity coordinate y. The quantity L was derived from the positive,between90and180°if gispositiveand jisnegative,
Committee’s original lightness scale factor,Λ. between180and270°ifgandjarebothnegative,andbetween
270 and 360° if g is negative and j is positive.
L 5 Λ 214.4 /=2 (1)
~ !
7.2.2 OSA Chroma:
where:
2 2 1/2
c 5 j 1g (10)
~ !
OSA
1/3 1/3
Λ 55.9 Y 22/310.042 Y 230 (2)
@ ~ ! #
0 0
7.2.3 Warning—Interpret OSA hue and chroma in visual
termscautiously,sincetheOSA-UCSsystemwasnotdesigned
isthemodifiedSemmelroth (6)formulathattakescrispening
to include these concepts.
ofcolordifferencesintoaccountforagraybackgroundof30%
luminous reflectance. The quantity Y in the equation forΛ is
obtained from a modified Sanders-Wyszecki (7) formula: 8. OSA-UCS Notations by Visual Means
2 2
Y 5 Y 4.4934 x 1 4.3034 y 2 4.276 xy (3) 8.1 Lighting and Viewing Conditions:
~
8.1.1 Observers—The specimens should be viewed by ob-
21.3744x 22.5643y11.8103)
servers with normal color vision.
8.1.2 Use of Natural Daylight—Place the specimen on a
whereY,x,yaretheCIE1964colorspecificationsofagiven
neutralbackgroundwith30%reflectance,equivalentto(0,0,0)
specimen. The usual subscript 10 has been omitted in the text
and illuminate it with natural daylight. Select a window in
and equations for clarity, but should be assumed to apply to all
whichthesunisnotshining.Anorthwindowisusuallychosen
chromaticitycoordinatesandtristimulusvalues.Thecalculated
inthenorthernhemisphere.Placeatablebythewindowsothat
value of Y refers to the tristimulus value Y of a gray specimen
light reaches the table top from the observer’s side, chiefly
that appears equally light to a non-gray object-color stimulus
from the sky, and at angles centering on 45° from the
(Y, x, y). The perfect reflecting diffuser illuminated by CIE
horizontal. Place a canopy of black cloth above the working
standard illuminant D yields the white specimen with
surfacetopreventerrorscausedbyreflectionsoflightfromthe
Y=100. The formula for Y is a chromatic enhancement of
ceilingorroomobjectsinthesurfaceofthespecimen.Viewthe
lightness.
specimen along a direction just far enough from the perpen-
7.1.1 The coordinates j and g are defined by the equations:
dicular to avoid reflection of the observer’s forehead. The
1/3 1/3 1/3
j 5 C~1.7R 18G 29.7B ! (4)
directions of illumination and viewing may be reversed with
equivalent results. When using reverse conditions, namely,
1/3 1/3 1/3
g 5 C 213.7R 117.7G 24B
~ !
illumination along the normal and viewing at 45° from the
normal, a black cloth should be hung opposite to the observer
where:
to avoid extraneous reflections being seen on the surfaces of
1/3
Λ ~Y 230!
the test specimens.
C 5 5110.042 (5)
1/3 1/3
5.9 Y 22/3 Y 22/3
~ !
0 0
8.1.3 Use ofArtificial Daylight—Astandard color-matching
R 50.799X10.4194Y 20.1648Z (6)
viewing booth with daylight-quality illumination (see Practice
D1535 and Practice D1729) may be used. The provisions of
G520.4493X11.3265Y10.0927Z
8.1.2 should be followed in other respects.
B520.1149X10.3394Y10.717Z
8.2 Determining the OSA-UCS Notation:
8.2.1 Display of Specimens—To visually determine the
7.1.2 The(R,G,B)tristimulusvaluesrefertoafundamental
OSA-UCS notation for an object-color test specimen, locate
system of primary stimuli whose (x, y) chromaticity coordi-
the OSA-UCS atlas samples that surround the test specimen in
nates are given as:
OSA-UCS space and interpolate among them to estimate the
x R 50.747 y R 50.253 (7)
~ ! ~ ! correct notation. The larger the number of OSA-UCS samples
available, the more accurate the estimate will be. Since there
x G 52.92 y G 524.54
~ ! ~ !
are only 420 full step color samples in the current atlas,
accuracy is limited. Around the neutral axis 134 half-step
x~B! 50.171 y~B! 50
samples have been added, making the placement of grayer
Note that when, as is often the case, the available data are in colors easier and more accurate.
the form Y, x, y, the other tristimulus values can be obtained
NOTE 2—In the OSA-UCS atlas, samples are arranged numerically by
from:
the first coordinate, L, representing lightness, in the three coordinate
notation. Within each lightness level, samples are arranged in horizontal
xY 1 2 x 2 y Y
~ !
X 5 andZ 5 (8) rows across the page by the second coordinate, j, and lastly by the third
y y
coordinate, g. Negative numbers precede positive numbers in each case.
Theatlasbeginswiththedarkestcolors,L=−7,andcontinuesthroughthe
7.2 OSA Hue and Chroma—It is convenient to define new
middle lightness, L=0, up to the lightest colors, L=5. OSA-UCS atlases
terms, analogous to those used in other systems such as
may be rearranged to place similar colors close to one another, making it
Munsell and CIE 1976, as follows:
easier to locate samples visually. See Appendix X2.
7.2.1 OSA Hue Angle or Hue:
8.2.1.1 Locate the atlas page(s) containing samples with
h 5 tan g/j (9) lightness closest to the lightness of the specimen. Select from
OSA
E1360 − 05 (2019)
among them the atlas sample that most closely resembles the the direction of hue difference from the test specimen and
test specimen in appearance. Compare the test specimen with choose an atlas sample with an OSA hue difference in the
the atlas sample either by placing the two colors edge to edge estimated direction. Place the test specimen between the two
or, if this is not possible, by using a mask that matches the atlassamplesandifthetestspecimenlookstoograyorhastoo
central gray, (0,0,0), to isolate equal areas of the specimen and much chroma, replace the second atlas sample with one of the
the sample(s) being compared. same OSA hue but hav
...