Colour vocabulary declines with age despite optical compensation

Aging shapes color vision and naming. In a large-scale unconstrained color-naming study with English (N=2420)

and Russian (N=2063) speakers aged 16–90 years, color vocabulary richness declined with age, in line with published

trajectories of lens density, pupil diameter, and tritan sensitivity, but not of macular pigment optical density.

Reliance on basic color terms increased with age in Russian but not in English, suggesting that shared perceptual

aging manifests as language-specific lexical usage. Category centroids shifted substantially in receptor-level (LMS)

coordinates but minimally in cone-opponent coordinates, and this stability extended beyond basic terms to 24

English and 27 Russian categories across the color solid, indicating compensationmechanisms that hold chromatic

ratios constant despite optical aging.