color-expert

Build palettes in OKLCH, which keeps lightness consistent across hues and avoids muddy mid-tones. Use tools like Poline for anchor-based interpolation, RampenSau for hue-cycling with easing, or Huetone for interactive LCH/OKLCH scale building.

Use OKLCH or color-mix(in oklab) for CSS gradients. RGB and HSL interpolation causes mid-gradient darkening and gray dead zones, while OKLAB-based interpolation keeps transitions perceptually smooth.

APCA is far more restrictive and perceptually accurate than WCAG. Only about 12% of random color pairs pass WCAG 4.5:1, while just 0.08% pass APCA 90. Use APCA 75 for fluent reading text and verify in both light and dark modes.

Pigment mixing follows spectral reflectance, not RGB averaging. RGB mixing curves inward and produces dull browns, while Kubelka-Munk spectral mixing (via Spectral.js or Mixbox) retains chroma and yields vivid secondaries like green from blue and yellow.

HSL is fine for quick color pickers and simple CSS tweaks where perceptual accuracy does not matter. Avoid it for palette generation, gradients, or accessibility work, since its lightness and saturation channels do not match human perception; use OKLCH or HSLuv instead.

Use Spectral.js (open source) or Mixbox (commercial), which implement Kubelka-Munk spectral mixing for realistic pigment behavior. For a painterly feel without spectral math, RYBitten converts between RGB and RYB with 26 historical color cubes.