Check WCAG contrast, simulate color blindness, and convert colors via color-mcp-server (uvx)

Recipe: WCAG contrast check, color blindness simulation, and color conversion via color-mcp-server (uvx)

Package: color-mcp-server v1.27.2 (PyPI) Transport: stdio via uvx color-mcp-server Auth: none — fully credential-free, uses TheColorAPI (free) for some tools; most run locally Tools: 9 total — tool_check_contrast, tool_simulate_color_blindness, tool_convert_color, tool_get_color_info, tool_get_color_info_local, tool_generate_palette, tool_get_complementary_color, tool_generate_gradient, tool_get_css_variables

1. WCAG Contrast Check

// request
{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"tool_check_contrast","arguments":{"foreground":"#1a1a2e","background":"#e0e0e0"}}}

// response
{"foreground":"#1a1a2e","background":"#e0e0e0","contrast_ratio":12.92,"wcag_aa_normal":true,"wcag_aa_large":true,"wcag_aaa_normal":true,"wcag_aaa_large":true,"rating":"AAA"}

Returns the contrast ratio and pass/fail for AA/AAA at normal and large text sizes.

2. Color Blindness Simulation

// request
{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"tool_simulate_color_blindness","arguments":{"color_hex":"#e74c3c","blindness_type":"deuteranopia"}}}

// response
{"original":"#e74c3c","simulated":"#acb840","blindness_type":"deuteranopia"}

Shows how #e74c3c (red) appears as #acb840 (olive/yellow) under deuteranopia (green-blindness). Supports: protanopia, deuteranopia, tritanopia, achromatopsia.

3. Color Format Conversion

// request
{"jsonrpc":"2.0","id":4,"method":"tools/call","params":{"name":"tool_convert_color","arguments":{"value":"#3498db","source":"hex","target":"hsl"}}}

// response
{"input":"#3498db","source":"hex","target":"hsl","result":"hsl(204, 70%, 53%)"}

Converts between hex, rgb, hsl, hsv.

Notes

• All responses include structuredContent with typed fields — no parsing needed
• isError: false on all three calls
• Server descriptions are in German (author is German-speaking), but tool behavior is universal
• Palette generation (tool_generate_palette) supports modes: monochrome, analogic, complement, triad, quad