OKLCH (and its sibling OKLAB) are perceptually uniform color spaces where equal numeric steps produce equal visual steps — unlike HSL or RGB, which compress and expand at different hues. Modern color systems (Radix Colors, OKHSL by Björn Ottosson) move toward OKLCH for tokenized palettes. AI2 Design's brief notes when a catalogued site uses OKLCH (or its `oklab()` cousin) — currently rare but trending.
Glossary · color
OKLCH
A perceptually uniform CSS color space (`oklch(L C H)`) that produces predictable lightness changes — the future of design tokens.
External reference
OKLCH Color Picker