Color Contrast

Developer REST API MCP

Compute the WCAG 2.1 contrast ratio between two colours (accepts #rgb, #rrggbb, and rgb()/rgba() formats) and report whether it passes AA/AAA for normal and large text.

This page documents the MCP tool findutils:color_contrast. See the REST reference →

Use in the browser View as Markdown

Call it over MCP

Tool name findutils:color_contrast · no API keys · 120 requests/min per IP

Claude Code

claude mcp add findutils --transport http https://mcp.findutils.com/

Claude Desktop — claude_desktop_config.json

{
  "mcpServers": {
    "findutils": {
      "url": "https://mcp.findutils.com/"
    }
  }
}

Raw JSON-RPC (any MCP client) — verified example

curl -X POST https://mcp.findutils.com/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/call",
    "params": {
      "name": "color_contrast",
      "arguments": {
        "foreground": "#000",
        "background": "#fff"
      }
    }
  }'

Input schema

Argument	Type	Required	Description
foreground	string	yes	Foreground / text colour.
background	string	yes	Background colour.

Example arguments (verified)

{
  "foreground": "#000",
  "background": "#fff"
}

Also a REST endpoint

The same tool answers plain HTTP at POST /api/tools/color-contrast/execute — no key, 60 requests/min.

Open the REST reference for Color Contrast →

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