Contrast Checker Mcp

This server gives Claude WCAG 2.1 contrast checking tools so it can verify color accessibility, compute ratios, and suggest compliant alternatives. It exposes three tools: check_contrast for ratios and pass/fail against AA/AAA thresholds, suggest_accessible_color to fix failing pairs while preserving hue, and parse_color for format conversion. It handles hex, rgb, hsl, named colors, and alpha transparency with proper compositing. Calculations match WebAIM's checker exactly, including the 0.03928 sRGB threshold and truncated ratios. Useful when building UIs, auditing designs, or having Claude generate accessible color schemes without leaving the conversation.