Colour measurement standards are the international agreements that make colour communication possible across industries, geographies, and supply chains. They define the illuminants, the observer functions, the measurement geometries, the reporting formats, and the tolerance criteria that allow a colour specification written in one country to be measured and verified in another. Without these standards, every colour management system would be an island — producing results that could not be meaningfully compared to any other system's results. Understanding the key standards that govern colour measurement helps production professionals work within the same framework as their customers, their suppliers, and the global certification bodies that audit their quality systems.
The most important body for colour measurement standards is the International Commission on Illumination (CIE), known by its French acronym. The CIE defines the mathematical models of colour that underpin all modern colour measurement — the Standard Observer functions, the standard illuminants, the L*a*b* colour space, and the Delta E colour difference formulas. Every X-Rite spectrophotometer is built around these CIE standards, ensuring that measurements are internationally comparable and traceably connected to the scientific foundation of colour science.
ISO 13655 — Spectral Measurement of Printed Colour
ISO 13655 is the international standard governing spectral measurement of printed media. It specifies the measurement geometry (M0, M1, M2, or M3 measurement conditions), the illuminant, and the measurement procedure for colour measurements on printed substrates. The most important distinction in ISO 13655 is between measurement conditions:
M0: Standard measurement condition, no UV filtration. The reference condition for most historical print colour measurement.
M1: Measurement under D50 illuminant with controlled UV content, designed to evaluate optical brighteners in the substrate accurately. This is the current recommended condition for ISO 12647-2 (offset print) compliance.
M2: Measurement with UV excluded — useful for evaluating ink colour independent of substrate optical brightener fluorescence.
M3: Measurement with polarised light, used primarily for wet ink measurement on press to eliminate specular reflection from fresh ink.
The eXact 2 spectrophotometer supports all four measurement conditions defined in ISO 13655, giving print operations the flexibility to meet customer specifications that may require specific measurement conditions for compliance verification.
ISO 12647 — Process Control for the Production of Halftone Colour Separations
The ISO 12647 series is the family of standards governing colour reproduction in different printing processes. ISO 12647-2 covers offset printing on sheet-fed and web presses; ISO 12647-6 covers flexographic printing. These standards define the target densities, dot gains, and colour values for standard press conditions — providing a common reference for characterising and verifying press performance.
Many commercial and packaging printers work toward ISO 12647 certification as evidence of a standardised, controlled printing process. This certification requires systematic measurement using calibrated spectrophotometers and densitometers at defined intervals, with results documented and verified against the standard's requirements. Color iQC software supports ISO 12647 compliant measurement workflows and reporting.
CGATS Standards
The Committee for Graphic Arts Technologies Standards (CGATS) produces standards relevant to the North American printing and imaging industry, many of which are referenced internationally. CGATS TR 016 (previously GRACoL) and CGATS TR 017 (previously SWOP) define specific press conditions for commercial offset printing and publication printing respectively, providing characterisation data and specification targets. These standards are often referenced in buyer requirements for print suppliers serving US and internationally aligned brand owners.
Standards for Non-Print Applications
Beyond printing, colour measurement standards exist for specific industrial applications. ASTM D2244 covers colour measurement in the coatings industry using spectrophotometers. Various automotive standards — from SMMT, OESA, and OEM-specific documents — govern colour measurement in vehicle manufacturing and component supply. Textile colour measurement is addressed by AATCC (American Association of Textile Chemists and Colorists) standards for instrumental evaluation of colour difference.
The handheld Ci series spectrophotometers are used across all of these non-print applications, with sphere geometry and aperture options suited to the diverse surface types encountered in plastics, coatings, and textile quality control.
CIE Illuminants and the Importance of D50
The CIE defines several standard illuminants used as reference light sources in colour measurement. D50 (5000K daylight simulation) is the standard illuminant for graphic arts, printing, and packaging colour work. D65 (6500K daylight) is more commonly used in other industries, including textiles and plastics. Illuminant A (2856K) represents incandescent lighting and is included in multi-illuminant assessments for metamerism checking.
Using consistent illuminants — both in instrument measurement and in light booths for visual assessment — is essential for results that are comparable between different parties in a supply chain. Specifying the illuminant as part of any colour tolerance specification eliminates one of the most common sources of colour communication confusion.
Conclusion
Colour measurement standards create the shared framework that makes global colour communication possible. Understanding which standards apply to your industry and production environment — and ensuring that your measurement instruments, software, and procedures comply with those standards — is the foundation of a colour quality program that is credible to your customers, effective in your production environment, and audit-ready for any quality certification your business pursues.