Overview
ISO 105-J05:2007 specifies a colorimetric method for estimating the magnitude (and optionally the direction) of a textile specimen’s change in perceived colour when the illumination chromaticity changes. Known as the CMCCON02 (Colour-Inconstancy Index), this method quantifies colour inconstancy - the change in appearance of a single specimen between a reference illuminant (CIE D65) and a chosen test illuminant. It is part of the ISO 105 series on textiles - tests for colour fastness.
Key topics and requirements
- Scope: Measures colour inconstancy of a single specimen (not metamerism between two specimens).
- Reference systems:
- Use the CIE 1964 (10°) Standard Colorimetric Observer for all tristimulus calculations.
- Reference illuminant: CIE Standard Illuminant D65; compare with an agreed test illuminant (e.g., A, D55, D75).
- Measurement inputs:
- Obtain tristimulus values (X, Y, Z) for the specimen under D65 and under the test illuminant, in accordance with ISO 105-J01.
- Tristimulus values for a perfect reflecting diffuser (p.r.d.) are used for normalization (Y = 100).
- Chromatic adaptation and transform:
- Apply a simplified CAT02 chromatic adaptation transform to compute the “corresponding colour” of the specimen (how it would appear in D65 when viewed under the test illuminant).
- Colour-difference calculation:
- Compute the colour difference between the measured D65 colour and the corresponding-colour-in-D65 using the colour-difference formula from ISO 105-J03 (examples use CIELAB ΔE and CMC(1:1)).
- The resulting metric is CMCCON02; near-zero indicates colour constancy between the two illuminants.
- Reporting requirements: Include standard reference, specimen ID, instrument details (geometry), test illuminant, origin of illuminant functions (e.g., ASTM E308-01), colour-difference formula used, CMCCON02 value, and optional ∆L*, ∆C*, ∆H* components.
Practical applications
- Quality control and colour assessment in textile manufacturing to evaluate how fabrics will appear under different lighting.
- Colour formulation and dye development to reduce unwanted shifts in appearance between retail, daylight and incandescent lighting.
- Textile testing laboratories that provide objective, instrument-based assessment of colour stability.
- Color scientists and instrument/software developers implementing CMCCON02 in spectrophotometer or colour-management tools.
Who should use this standard
- Textile technologists and QC engineers
- Colourists and dyers
- Accredited textile test laboratories
- Spectrophotometer and colour‑measurement software developers
- Researchers in colourimetry and appearance modelling
Related standards
- ISO 105-J01 - General principles for measurement of surface colour
- ISO 105-J03 - Calculation of colour differences (used to compute CMCCON02)
- CIECAM02 / CIE Publ. 159 - Colour appearance model (background on CAT02)
- ASTM E308-01 - Weighting functions for computing colours (illuminant data)
Keywords: ISO 105-J05:2007, CMCCON02, colour inconstancy, textiles colour fastness, CAT02, CIE D65, colour-difference, spectrophotometer.