Color Contrast API

POST https://api.findutils.com/api/tools/color-contrast/execute

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.

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Request body

application/json

foreground

string required

Foreground / text colour.
background

string required

Background colour.

Example arguments

Verified

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

A2ui Basic Catalog Returns the authoritative basic-catalog JSON Schema (components, functions, theme) for the requested A2UI version.
A2ui Diff Computes a structural diff between two A2UI JSONL payloads: surfaces added/removed, components added/removed/changed (by id), data-model…
A2ui Examples Returns one or more canonical A2UI JSONL examples matching a pattern (form, list, wizard, modal, chat, dashboard, checkout, typeahead…
A2ui Prompt Generates a drop-in LLM system prompt that teaches the model to output valid A2UI JSONL: includes the basic-catalog component / function…
A2ui Spec Returns A2UI protocol documentation for a given spec version and section.
A2ui Validate Validates a JSONL A2UI payload against the basic catalog (or a custom catalog) and returns any errors, warnings, or info messages…

curl -X POST https://api.findutils.com/api/tools/color-contrast/execute \
  -H "Content-Type: application/json" \
  -d '{
    "foreground": "#000",
    "background": "#fff"
  }'

const response = await fetch('https://api.findutils.com/api/tools/color-contrast/execute', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({"foreground":"#000","background":"#fff"}),
});
const data = await response.json();

import requests

response = requests.post(
    "https://api.findutils.com/api/tools/color-contrast/execute",
    json={"foreground":"#000","background":"#fff"},
)
data = response.json()

$ch = curl_init('https://api.findutils.com/api/tools/color-contrast/execute');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Content-Type: application/json'],
    CURLOPT_POSTFIELDS => '{"foreground":"#000","background":"#fff"}',
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

Also an MCP tool

Call color_contrast from Claude, Cursor or any MCP client. Same arguments, same output.

https://mcp.findutils.com

MCP reference

Rate limit: 60 a minute, per IP
Auth: None
REST id: color-contrast
MCP name: color_contrast
Category: Developer
Machine-readable: openapi.json · markdown.md

Request body

Example arguments

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