CIE LUV

A perceptually uniform color space defined by the International Commission on Illumination (CIE) that separates color into luminance (L*) and two chromaticity coordinates (u* and v*). Unlike RGB, which is tied to display hardware and not perceptually uniform, equal distances in CIE LUV correspond approximately to equal perceived color differences. This property makes it valuable for accessibility applications such as modelling color vision deficiencies, because color differentiation thresholds can be measured and compared consistently. Colors of equal luminance can be found by holding L* constant, allowing researchers to isolate chromatic differences from brightness differences when testing color perception.