ASTM D2244-09a

Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates

SIGNIFICANCE AND USE
The original CIE color scales based on tristimulus values X, Y, Z and chromaticity coordinates x, y are not uniform visually. Each subsequent color scale based on CIE values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.
For uniformity of practice, the CIE recommended in 1976 the use of two color metrics. The CIELAB metric, with its associated color-difference equation, has found wide acceptance in the coatings, plastics, textiles and related industries. While the CIELAB equation has not completely replaced the use of Hunter LH, aH, bH, this older scale is no longer recommended for other than legacy users, and is therefore included in an Appendix for historical purposes. The CIELAB color-difference equation is also not recommended in this practice for use in describing small and moderate color differences (differences with magnitude less than 5.0 Δ E*ab units). The four more recently defined equations, documented here, are highly recommended for use with color-differences in the range of 0.0 to 5.0 ΔE*ab units.
Users of color tolerance equations have found that, in each system, summation of three, vector color-difference components into a single scalar value is very useful for determining whether a specimen color is within a specified tolerance from a standard. However, for control of color in production, it may be necessary to know not only the magnitud...
SCOPE
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of color tolerances and small color differences between opaque specimens such as painted panels, plastic plaques, or textile swatches. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D 4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space  (1), CMC tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000 color difference units (5).
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the correlation between the magnitude of a measured color difference and its commercial acceptability.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

General Information

• Status: Historical
• Publication Date: 31-Jul-2009
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.04 - Color and Appearance Analysis

Relations

• Replaces: ASTM D2244-09 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
• Effective Date: 01-Aug-2009
• Referred By: ASTM F2957-13(2019)e1 - Standard Specification for Ornamental Aluminum Fence Systems
• Effective Date: 01-Aug-2009
• Referred By: ASTM D6531-00(2019) - Standard Test Method for Relative Tinting Strength of Aqueous Ink Systems by Instrumental Measurement
• Effective Date: 01-Aug-2009
• Referred By: ASTM D3134-15(2019) - Standard Practice for Establishing Color and Gloss Tolerances
• Effective Date: 01-Aug-2009
• Referred By: ASTM D6695-16 - Standard Practice for Xenon-Arc Exposures of Paint and Related Coatings
• Effective Date: 01-Aug-2009
• Referred By: ASTM C1510-01(2020) - Standard Test Method for Color and Color Difference of Whitewares by Abriged Spectrophotometry
• Effective Date: 01-Aug-2009
• Referred By: ASTM D2248-01a(2018) - Standard Practice for Detergent Resistance of Organic Finishes
• Effective Date: 01-Aug-2009
• Referred By: ASTM D2066-07(2020) - Standard Test Methods for Relative Tinting Strength of Paste-Type Printing Ink Dispersions
• Effective Date: 01-Aug-2009
• Referred By: ASTM F2589-16(2021) - Standard Specification for Ornamental Fences Employing Steel Tubular Pickets
• Effective Date: 01-Aug-2009
• Referred By: ASTM D279-02(2023) - Standard Test Methods for Bleeding of Pigments
• Effective Date: 01-Aug-2009
• Referred By: ASTM D822/D822M-13(2018) - Standard Practice for Filtered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
• Effective Date: 01-Aug-2009
• Referred By: ASTM D6577-15(2019) - Standard Guide for Testing Industrial Protective Coatings
• Effective Date: 01-Aug-2009
• Referred By: ASTM D5531-17(2023) - Standard Guide for Preparation, Maintenance, and Distribution of Physical Product Standards for Color and Geometric Appearance of Coatings
• Effective Date: 01-Aug-2009
• Referred By: ASTM D2745-00(2023) - Standard Test Method for Relative Tinting Strength of White Pigments by Reflectance Measurements
• Effective Date: 01-Aug-2009
• Referred By: ASTM E308-22 - Standard Practice for Computing the Colors of Objects by Using the CIE System
• Effective Date: 01-Aug-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D2244–09a
Standard Practice for
Calculation of Color Tolerances and Color Differences from
1
Instrumentally Measured Color Coordinates
This standard is issued under the fixed designation D2244; 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.
This standard has been approved for use by agencies of the Department of Defense.
INTRODUCTION
This practice originally resulted from the consolidation of a number of separately published
methodsfortheinstrumentalevaluationofcolordifferences.Asrevisedin1979,itincludedfourcolor
spaces in which color-scale values could be measured by instruments, many of which were obsolete,
and the color differences calculated by ten equations for different color scales. The sections on
apparatus,calibrationstandardsandmethods,andmeasurementproceduresservedlittlepurposeinthe
lightofmoderncolor-measurementtechnology.Therevisionpublishedin1993omittedthesesections,
and limited the color spaces and color-difference equations considered, to the three most widely used
inthepaintandrelatedcoatingsindustry.Apreviousrevisionaddedtwonewcolortoleranceequations
and put two of the color difference equations from the 1993 version in an informative appendix for
historical purposes.
1. Scope* the correlation between the magnitude of a measured color
difference and its commercial acceptability.
1.1 Thispracticecoversthecalculation,frominstrumentally
1.3 This standard does not purport to address all of the
measured color coordinates based on daylight illumination, of
safety concerns, if any, associated with its use. It is the
color tolerances and small color differences between opaque
responsibility of the user of this standard to establish appro-
specimens such as painted panels, plastic plaques, or textile
priate safety and health practices and determine the applica-
swatches. Where it is suspected that the specimens may be
bility of regulatory requirements prior to use.
metameric, that is, possess different spectral curves though
visuallyalikeincolor,PracticeD4086shouldbeusedtoverify
2. Referenced Documents
instrumentalresults.Thetolerancesanddifferencesdetermined
3
2.1 ASTM Standards:
by these procedures are expressed in terms of approximately
D1729 Practice for Visual Appraisal of Colors and Color
uniform visual color perception in CIE 1976 CIELAB
2 Differences of Diffusely-Illuminated Opaque Materials
opponent-color space (1), CMC tolerance units (2), CIE94
D4086 Practice for Visual Evaluation of Metamerism
tolerance units (3), the DIN99 color difference formula given
E284 Terminology of Appearance
in DIN6176 (4), or the new CIEDE2000 color difference units
E308 Practice for Computing the Colors of Objects by
(5).
Using the CIE System
1.2 For product specification, the purchaser and the seller
E805 Practice for Identification of Instrumental Methods of
shall agree upon the permissible color tolerance between test
Color or Color-Difference Measurement of Materials
specimen and reference and the procedure for calculating the
E1164 Practice for Obtaining Spectrometric Data for
colortolerance.Eachmaterialandconditionofusemayrequire
Object-Color Evaluation
specific color tolerances because other appearance factors, (for
2.2 Other Standards:
example, specimen proximity, gloss, and texture), may affect
DIN 6176 Farbmetrische, Bestimmung von Farbabständen
4
bei Körperfarben nach der DIN99-Formel
1
This practice is under the jurisdiction ofASTM Committee E12 on Color and
Appearance and is the direct responsibility of Subcommittee E12.04 on Color and
3
Appearance Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Aug. 1, 2009. Published August 2009. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1964. Last previous edition approved in 2009 as D2244–09. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D2244-09A. the ASTM website.
2 4
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof Available from Beuth Verlag GmbH, 10772, Berlin, Germany, http://
this standard. www.beuth.de/.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

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D2244–09a
3. Terminology had weighting factors applied to provide some degree of
uniformity so that color differences in various regions of color
3.1 Terms and definitions in Terminology E284 are appli-
spacewillbemore
...

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D2244–09 Designation:D2244–09a
Standard Practice for
Calculation of Color Tolerances and Color Differences from
1
Instrumentally Measured Color Coordinates
This standard is issued under the fixed designation D2244; 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.
This standard has been approved for use by agencies of the Department of Defense.
INTRODUCTION
This practice originally resulted from the consolidation of a number of separately published
methodsfortheinstrumentalevaluationofcolordifferences.Asrevisedin1979,itincludedfourcolor
spaces in which color-scale values could be measured by instruments, many of which were obsolete,
and the color differences calculated by ten equations for different color scales. The sections on
apparatus,calibrationstandardsandmethods,andmeasurementproceduresservedlittlepurposeinthe
lightofmoderncolor-measurementtechnology.Therevisionpublishedin1993omittedthesesections,
and limited the color spaces and color-difference equations considered, to the three most widely used
inthepaintandrelatedcoatingsindustry.Apreviousrevisionaddedtwonewcolortoleranceequations
and put two of the color difference equations from the 1993 version in an informative appendix for
historical purposes.
1. Scope*
1.1 This practice covers the calculation, from instrumentally measured color coordinates based on daylight illumination, of
colortolerancesandsmallcolordifferencesbetweenopaquespecimenssuchaspaintedpanels,plasticplaques,ortextileswatches.
Whereitissuspectedthatthespecimensmaybemetameric,thatis,possessdifferentspectralcurvesthoughvisuallyalikeincolor,
Practice D4086 should be used to verify instrumental results. The tolerances and differences determined by these procedures are
2
expressed in terms of approximately uniform visual color perception in CIE 1976 CIELAB opponent-color space (1), , CMC
tolerance units (2), CIE94 tolerance units (3), the DIN99 color difference formula given in DIN 6176 (4), or the new CIEDE2000
color difference units (5).
1.2 For product specification, the purchaser and the seller shall agree upon the permissible color tolerance between test
specimen and reference and the procedure for calculating the color tolerance. Each material and condition of use may require
specific color tolerances because other appearance factors, (for example, specimen proximity, gloss, and texture), may affect the
correlation between the magnitude of a measured color difference and its commercial acceptability.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
requirements prior to use.
2. Referenced Documents
3
2.1 ASTM Standards:
D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D4086 Practice for Visual Evaluation of Metamerism
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
E805 Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of Materials
1
This practice is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.04 on Color and
Appearance Analysis.
Current edition approved JulyAug. 1, 2009. Published JulyAugust 2009. Originally approved in 1964. Last previous edition approved in 20072009 as D2244–07
´1.D2244–09.
2
The boldface numbers in parentheses refer to the list of references at the end of this standard.
3
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail] Annual Book ofASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
D2244–09a
E1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation
2.2 Other Standards:
4
DIN 6176 Farbmetrische, Bestimmung von Farbabständen bei Körperfarben nach der DIN99-Formel
3.
...