Color Palette

Generate harmonious color palettes and verify accessibility compliance.

Instructions

1. Generate palette from a base color (hex, RGB, HSL, or name):

   • Complementary: Opposite on color wheel (+180°)
   • Analogous: Adjacent colors (±30°)
   • Triadic: Three evenly spaced (120° apart)
   • Split-complementary: Base + two adjacent to complement
   • Monochromatic: Shades/tints of one hue

2. Brand palette: From brand description or existing colors, suggest:

   • Primary, Secondary, Accent, Background, Text, Error, Success

3. WCAG Accessibility Check: For any fg/bg pair, calculate contrast ratio:

   Linearize: c ≤ 0.04045 → c/12.92, else ((c+0.055)/1.055)^2.4
   Luminance: L = 0.2126*R + 0.7152*G + 0.0722*B
   Ratio: (L_light + 0.05) / (L_dark + 0.05)
   

   • AA normal text: ≥ 4.5:1
   • AA large text: ≥ 3:1
   • AAA normal text: ≥ 7:1

4. Output format:

   🎨 Palette: Analogous from #3B82F6
   | Role      | Hex     | RGB           | Name       |
   |-----------|---------|---------------|------------|
   | Primary   | #3B82F6 | 59, 130, 246  | Blue       |
   | Secondary | #6366F1 | 99, 102, 241  | Indigo     |
   | Accent    | #22D3EE | 34, 211, 238  | Cyan       |
   
   ✅ #1E293B on #F8FAFC → 15.4:1 (AAA Pass)
   ❌ #94A3B8 on #F8FAFC → 2.8:1 (AA Fail — try #64748B)
   

5. Export: Generate CSS custom properties or Tailwind config:

   :root { --color-primary: #3B82F6; --color-secondary: #6366F1; }
   

Edge Cases

• Dark mode: Generate both light and dark variants
• Color blindness: Warn if palette relies on red/green distinction alone
• Near-failing contrast: Suggest nearest passing alternative

Requirements

• No dependencies — pure calculation
• No API keys needed