colorspecification

Colorspecification is the process of defining a color for a product, digital image, or communication to ensure consistent reproduction across devices and media. It combines color models, measurement data, tolerances, and communication protocols to translate subjective perception into objective parameters.

Color models and spaces: Simple device-dependent spaces like sRGB or Adobe RGB are used for digital work, while device-independent spaces such as CIE Lab or CIE Luv describe color independent of viewing device. Subtractive and additive systems (CMYK, RGB) reflect printing and display realities, and perceptual spaces aim to match human vision.

Measurement and tolerances: Color can be specified with numerical values from spectrophotometers or colorimeters. CIE XYZ and CIE Lab values are common, and delta E quantifies perceptual difference. Tolerances define acceptable deviations in production (e.g., ΔE00 <= 2 in high-end printing).

Standards and systems: Illuminants (D65) and a standard observer underpin color calculations. ICC profiles enable color management across devices. External color specifications include Pantone, RAL, or NCS, each with defined color sets used for branding, coatings, or interiors.

Workflow and challenges: A typical workflow specifies the target color, selects spaces and tolerances, and creates an ICC-profile-based workflow. Verification uses instruments to measure produced colors and adjust as needed. Common issues include metamerism, lighting variations, and device calibration.