ccr

A command-line tool for checking WCAG color contrast ratios. Install nothing — just run:

npx @siluat/color-contrast-cli '#708090' '#ffffff'

Contrast ratio: 3.94:1
Normal text: Fail ✗
Large text:  AA ✓

Why ccr?

Gate your pipeline with --level AA exit codes. Pipe --json output to other tools for automated reporting.

When contrast fails, --suggest finds the closest accessible color. Adjusts only OkLCH lightness to preserve the original hue and saturation.

Audit an entire design system palette at once with --batch. Supports comments, blank lines, and mixed color formats.

#hex, rgb(), hsl(), hwb(), lab(), lch(), oklab(), oklch(), and named colors — broad CSS Color Level 4 coverage.

Install globally

npm install -g @siluat/color-contrast-cli

Check a color pair

ccr '#333' '#fff'

Get a fix for failing contrast

ccr '#999' '#fff' --suggest --level AA

Audit a palette file

ccr --batch < palette.txt

Read the Getting Started guide for more details, or jump to the CLI Reference for the full option list.

The computation engine is also available as a standalone JavaScript/TypeScript library — @siluat/color-contrast — for programmatic use.