Designation:D2244−15´1StandardPracticeforCalculationofColorTolerancesandColorDifferencesfromInstrumentallyMeasuredColorCoordinates1ThisstandardisissuedunderthefixeddesignationD2244;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.ε1NOTE—EditorialcorrectionsweremadethroughoutinJune2015.INTRODUCTIONThispracticeoriginallyresultedfromtheconsolidationofanumberofseparatelypublishedmethodsfortheinstrumentalevaluationofcolordifferences.Asrevisedin1979,itincludedfourcolorspacesinwhichcolor-scalevaluescouldbemeasuredbyinstruments,manyofwhichwereobsolete,andthecolordifferencescalculatedbytenequationsfordifferentcolorscales.Thesectionsonapparatus,calibrationstandardsandmethods,andmeasurementproceduresservedlittlepurposeinthelightofmoderncolor-measurementtechnology.Therevisionpublishedin1993omittedthesesections,andlimitedthecolorspacesandcolor-differenceequationsconsidered,tothethreemostwidelyusedinthepaintandrelatedcoatingsindustry.Apreviousrevisionaddedtwonewcolortoleranceequationsandputtwoofthecolordifferenceequationsfromthe1993versioninaninformativeappendixforhistoricalpurposes.1.Scope*1.1Thispracticecoversthecalculation,frominstrumentallymeasuredcolorcoordinatesbasedondaylightillumination,ofcolortolerancesandsmallcolordifferencesbetweenopaquespecimenssuchaspaintedpanels,plasticplaques,ortextileswatches.Whereitissuspectedthatthespecimensmaybemetameric,thatis,possessdifferentspectralcurvesthoughvisuallyalikeincolor,PracticeD4086shouldbeusedtoverifyinstrumentalresults.ThetolerancesanddifferencesdeterminedbytheseproceduresareexpressedintermsofapproximatelyuniformvisualcolorperceptioninCIE1976CIELABopponent-colorspace(1),2CMCtoleranceunits(2),CIE94toleranceunits(3),theDIN99colordifferenceformulagi...
