Color System

Produce a contrast-verified color token file for this codebase — ramps, semantic layer, dark mode — with the math shown, not a color-theory lecture. Governing principle: color is a system, not a list: every hue ships as a full lightness ramp, components consume only semantic tokens, and no text/background pair ships without a computed contrast ratio.

When to use / handoffs

• Use for palettes, ramps, dark mode, contrast fixes, status/interactive colors, theming.
• No token infrastructure exists → run skills/frontend-design/design-foundation first, or create the color slice as its start.
• "Everything is grey and flat / can't tell what's important" is usually hierarchy, not palette → skills/frontend-design/visual-hierarchy-refactoring.
• Full WCAG audit beyond color → skills/frontend-design/accessibility-excellence.

Step 1 — Inspect the codebase

1. Harvest the palette. Grep for #[0-9a-fA-F]{3,8}\b, rgba?\(, hsla?\(, oklch\( across source + config. Deduplicate, count frequencies. Cluster near-identical values (ΔL < ~5) — each cluster is one intended color that drifted.
2. Read existing tokens. Tailwind theme.colors / @theme variables / CSS custom properties. Determine whether ramps exist or just single hexes.
3. Identify the de facto brand color — the most-used saturated hue.
4. Check dark mode state: dark: classes, prefers-color-scheme, a .dark block.
5. Spot-check contrast on the 3–5 most common text/background pairs found in code — compute the WCAG ratios; failures go straight into your rationale.

Step 2 — Intake

Ask in one batch, only what's missing: brand color to keep, or pick fresh (and the personality if picking: trustworthy/energetic/premium/friendly), and dark mode: now, later, or never. Infer the rest. Don't stall: with a clear de facto brand color, keep it, state the assumption, proceed.

Step 3 — Build the system

1. Brand ramp. Expand the brand color into an 11-step lightness ramp (50–950), holding hue roughly constant, adjusting chroma down at the extremes. Base usable for white text lands around step 600 for most hues.
2. Neutral ramp — tinted, never true grey. Desaturate the brand hue heavily (roughly 5–15% saturation) and build gray-50…950 from it. #808080 and pure #000 are banned; they read as foreign next to any brand color.
3. Accent/secondary (only if the product needs one). Choose by harmony rule: analogous (±30–60°) for cohesive/calm products; complementary (~180°) for a high-energy CTA accent used sparingly; triadic when the UI must color-code ≥3 categories. Don't add hues without a job.
4. Status colors. Success ≈ green, warning ≈ amber, error ≈ red, info ≈ cyan/blue — nudged toward the brand's temperature, each with at least a 100/600/700 mini-ramp (background tint, base, text-on-tint).
5. Semantic layer. bg-primary/secondary/tertiary, text-primary/secondary/tertiary/disabled/inverse, border-primary/focus, interactive-primary/hover/active/disabled — mapped from the ramps. Components never touch ramp values directly.
6. Dark mode (if in scope). Remap semantic tokens only: backgrounds to gray-900/950 (never #000), text to gray-50/300, brand shifted one step lighter (light mode's 600 → dark's 500) and slightly desaturated if it vibrates. Re-verify every pair — light-mode ratios don't transfer.
7. Verify contrast on every shipped pairing. Compute WCAG relative-luminance ratios: ≥4.5:1 normal text, ≥3:1 large text (≥24px, or ≥18.7px bold) and UI components/focus rings. That's the pass/fail gate. Where a pair passes WCAG but looks weak (light text on saturated mid-tone), treat APCA (Lc ≈ 60+ for body) as an advisory tiebreaker and darken a step.
8. Color-blind safety. Status colors must not be the only signal — pair with icon/label (red/green alone fails ~8% of male users). Avoid red-vs-green as the sole category distinction; blue/orange is the safest contrast pair.

Canonical shape (CSS variables; adapt to detected stack)

:root {
  --brand-600: #2563EB;  --brand-700: #1D4ED8;   /* full 50–950 ramp in the real file */
  --gray-600: #475569;   --gray-900: #0F172A;    /* brand-tinted neutrals, full ramp */
  --red-600: #DC2626;    --red-100: #FEE2E2;     /* status mini-ramps: green/amber/red/cyan */

  --color-bg-primary: #FFFFFF;
  --color-text-primary: var(--gray-900);      /* on bg-primary: 17.8:1 ✓ */
  --color-text-secondary: var(--gray-600);    /* on bg-primary: 7.6:1 ✓ */
  --color-interactive-primary: var(--brand-600); /* white on it: 5.2:1 ✓ */
}
.dark {
  --color-bg-primary: var(--gray-950);
  --color-text-primary: var(--gray-50);
  --color-interactive-primary: var(--brand-500);
}

Harmony theory, color psychology, ramp-construction technique, and color-blind palettes: references/color-theory.md.

Step 4 — Wire in and migrate

Write tokens into the detected entry point (extend, don't fork). Migrate the top drift clusters from Step 1 in 1–3 high-traffic files; map the rest.

Required output format

Deliver code plus this summary:

## Color tokens
[file path + full code]

## Palette decisions
- Brand: [hex] — [kept from code / chosen for [personality]]
- Neutrals: tinted toward [hue]
- Harmony: [mono/analogous/complementary/triadic] because [job it does]
- Dark mode: [shipped/deferred] — strategy: [.dark class / media query]

## Contrast verification
| Pair | Ratio | Standard | Pass |
| text-primary on bg-primary (light) | 17.8:1 | 4.5:1 | ✓ |
| white on interactive-primary | 5.2:1 | 4.5:1 | ✓ |
| text-secondary on bg-primary (dark) | ... | ... | ... |
[every shipped text and UI pairing, both modes]

## Migration map
| Found (cluster) | Count | Replace with |
| #3B82F6 / #3b82f7 / #3a80f0 | 23 | var(--color-interactive-primary) |
| ... |

## Migrated now
[files edited]

Quality bar (check before delivering)

• Every text/background pair shipped has a computed ratio in the table; all ≥4.5:1 (normal) / ≥3:1 (large + UI), both modes
• Neutrals brand-tinted; no #808080, no pure #000 backgrounds
• Every hue exists as a ramp, not a lone hex; each hue has a stated job
• Components/examples reference only semantic tokens
• Status meaning never carried by color alone (icon/label paired)
• Dark mode: backgrounds are dark grey, brand lightened a step, all pairs re-verified
• Focus indicator color ≥3:1 against adjacent colors
• Migration map covers every drift cluster found in Step 1

Integration

• Consumes: token skeleton from skills/frontend-design/design-foundation; text sizes (for the large-text contrast threshold) from skills/frontend-design/typography-system.
• Produces: color tokens consumed by skills/frontend-design/visual-hierarchy-refactoring (lightness-based contrast hierarchy), skills/frontend-design/component-architecture (component color bindings), and audited by skills/frontend-design/accessibility-excellence.

References

• references/color-theory.md — harmony techniques with examples, color psychology by hue, how to construct a ramp by hand, color-blind-safe palettes, and dark-mode pitfalls in depth. Read when picking a palette from scratch or debugging a ramp that looks wrong.