OKLCH (color space)
Perceptually uniform color space (Lightness, Chroma, Hue + alpha) standardized by the CSS Color Module Level 4. Adopted by Tailwind v4 (`@theme { --color-primary: oklch(...) }`) and DTCG color module v2025.10. Guarantees `oklch(L 0.2 240)` stays perceived identical in lightness regardless of hue, real gain vs RGB/HSL for scalable palettes.
Strengths
- Perceptually uniform, L lightness stable regardless of H hue
- Wide gamut (P3, Rec2020), accesses colors outside sRGB on modern displays
- Adopted by Tailwind v4 + DTCG color module v2025.10, AI-friendly pipeline
Limitations
- Learning curve: thinking in L/C/H instead of R/G/B takes 1-2 weeks
- Legacy tools (old Sketch, old CSS generators) do not support, hex fallback still needed for very old browsers
Best for
- DS with complex palettes (50-900 ramps, dark/light, multi-brand)
- AI-friendly token pipelines with Tailwind v4 + DTCG