Color Space

A mathematical model that describes the range of colours that can be represented as numerical values, typically using three or more coordinates. Common colour spaces include RGB (red, green, blue), used in digital displays; CMYK (cyan, magenta, yellow, key/black), used in printing; HSB/HSV (hue, saturation, brightness/value); and CIE L*a*b*, a perceptually uniform space where numerical distance between colours approximates perceived colour difference. In accessibility, understanding colour spaces is important for evaluating colour contrast ratios, simulating colour vision deficiencies, and developing recolouring algorithms. Dichromats perceive colour in a reduced two-dimensional colour space compared to the three-dimensional space of typical trichromatic vision.