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

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  (), CMC tolerance units (), CIE94 tolerance units  (), the DIN99 color difference formula given in DIN 6176 (), or the new CIEDE2000 color difference units  ().
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.
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.

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Publication Date
30-Sep-2005
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ASTM D2244-05 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D2244–05
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 (e) 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 PracticeforIdentificationofInstrumentalMethodsof
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
E 1164 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 Oct. 1, 2005. Published November 2005. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
e1
approved in 1964. Last previous edition approved in 2002 as D2244–02 . Standards volume information, refer to the standard’s Document Summary page on
2
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof the ASTM website.
4
this standard. Available from Beuth Verlag GmbH, 10772 Berlin, Germany.
*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.
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D2244–05
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-
spacewillbemorenearlycomparable.Ontheotherhand,color
cable to th
...

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