Color Expert — скилл

---
name: color-expert
description: Use when working with color naming, color theory, color spaces, color definitions, or any task involving color knowledge - palettes, ramps, gradients, conversions, accessibility, perceptual matching, pigment mixing, print-vs-screen color, CSS color syntax, or historical color terminology. Use this skill whenever the user is choosing, comparing, generating, naming, converting, or explaining colors, even if they do not explicitly ask for "color theory."
---

# Color Expert

A comprehensive knowledge base for color-related work. See `references/INDEX.md` for 140+ detailed reference files; this skill file contains the essential knowledge to answer most questions directly.

## How to Use This Skill

Match the response to the user's explicit request and clearly implied constraints from context. Five common modes:

**Concrete design or art project** — "help me pick colors for my logo / poster / illustration / app." Ask about medium (print, screen, paint, mixed), brand or mood, audience, accessibility needs, and any existing colors to harmonize with. Then propose. Don't lecture about CIE 1931 or OKLCH internals unless asked. Recommend specific tools and palettes that fit the constraints, not generic theory.

**Design system, ramps, or theme tokens** — "build me a 9-step accent scale", "palette for light + dark mode", "Tailwind/Radix-style ramps", "what's the right gray ramp for our brand?" Prioritize in this order:

- Use OKLCH to build perceptually uniform scales (consistent lightness across hues, no muddy mid-tones).
- Build a token graph: reference tokens (palette) → semantic tokens (surface, on-surface, accent, success, warning, danger) → component usage; see *Implementation Guidance* below.
- Verify every text/background pair against APCA or WCAG in both light and dark.

The test for a sequential ramp is **flat perceptual derivative** — plot the perceptual step size between consecutive samples; it should be a horizontal line, in color *and* in grayscale. Bumps are regions where the ramp exaggerates change that isn't in the data (this is jet's core failure, not its ugliness).

## Color Spaces — What to Use When

| Task                            | Use                                    | Why                                                                       |
| ------------------------------- | -------------------------------------- | ------------------------------------------------------------------------- |
| Perceptual color manipulation   | **OKLCH**                              | Best uniformity for lightness, chroma, hue. Fixes CIELAB's blue problem.  |
| CSS gradients & palettes        | **OKLCH** or `color-mix(in oklab)`     | No mid-gradient darkening like RGB/HSL                                    |
| Gamut-aware color picking       | **OKHSL / OKHSV**                      | Ottosson's picker spaces — cylindrical like HSL but perceptually grounded |
| Normalized saturation (0-100%)  | **HSLuv**                              | CIELUV chroma normalized per hue/lightness. HPLuv for pastels.            |
| Print workflows                 | **CIELAB D50**                         | ICC standard illuminant                                                   |
| Screen workflows                | **CIELAB D65** or OKLAB                | D65 = screen standard                                                     |
| Cross-media appearance matching | **CAM16 / CIECAM02**                   | Accounts for surround, adaptation, luminance, and viewing conditions      |
| HDR                             | **Jzazbz / ICtCp**                     | Designed for extended dynamic range                                       |