donatj / alike-color-finder

v0.9.0 2026-09-30 16:15 UTC

Requires

• php: >=7.4
• composer-runtime-api: ^2.2
• donatj/flags: ^1.6

Requires (Dev)

• corpus/coding-standard: ^0.9.0
• donatj/drop: ^1.1
• friendsofphp/php-cs-fixer: ^3.95
• php-parallel-lint/php-parallel-lint: ^1.4
• phpstan/phpstan: ^2.2
• phpunit/phpunit: ^8.5 || ^9.6 || ^10.5
• squizlabs/php_codesniffer: ^3.6

MIT

• Jesse Donat

• cli
• css
• ci
• color
• color-difference

Published on Packagist.org on 2026-09-30 16:27 UTC

README

Alike Color Finder is a command-line tool for CI that detects nearly identical colors before they become visual drift. It scans CSS and CSS-like files, directories, or standard input; reports color pairs at or below a chosen difference tolerance; and can fail a build when it finds them.

It understands hex and named colors; rgb(), rgba(), hsl(), hsla(), hwb(), lab(), lch(), oklab(), oklch(), and color() functions; and CSS Color Level 4 wide-gamut spaces including Display P3, Rec2020, and ProPhoto RGB.

Choose CIEDE2000 + alpha (the default), CIE94 + alpha, or an absolute color-difference strategy with --strategy.

Prefer a browser? A web-based interface is also available.

Why

Nearly identical colors tend to accumulate in long-lived stylesheets. This began as a small script for finding them, then grew into a tool that can enforce a color-consistency rule in CI.

It is intended to make accidental color drift visible before it ships.

Requirements

• PHP 7.4+ with CLI and SPL support

Installation

Install alike globally:

composer global require donatj/alike-color-finder

Or add it to a project as a vendor binary:

composer require --dev donatj/alike-color-finder

Usage

The examples below use a global installation. For a project dependency, invoke vendor/bin/alike instead.

Scan files or directories:

alike main.css shared.scss styles/

Or pipe CSS through standard input:

css-generating-process | alike

The default ciede2000 strategy reports colors whose difference is at most 4. Lower --tolerance to require closer matches, or choose cie94 or actual with --strategy.

alike --tolerance 1 styles/

Continuous integration

By default, alike exits with 2 when it finds a qualifying color pair or encounters an extraction error, which is suitable for most CI systems. Set --exit-code to another status, or to 0 to report findings without failing the build.

Options

Run alike --help for the complete CLI reference. The core options are:

Option	Description
--strategy	Difference strategy: ciede2000 (default; perceptual alias), cie94, or actual.
--tolerance	Maximum computed difference considered alike; defaults to 4.
--exit-code	Exit status used when findings or extraction errors occur; defaults to 2. Set to 0 to disable failure.
--pattern	Regular expression for files discovered when scanning a directory.

Example output

Scanning a CSS file:

alike main.css
                    (4) #e3e3e3                    (4) #e4e4e4   Δ: 0.352
                        #e3e3e3                        #e4e4e4

                    (4) #e3e3e3                    (4) #e5e5e5   Δ: 0.705
                        #e3e3e3                        #e5e5e5

                    (4) #e4e4e4                    (4) #e5e5e5   Δ: 0.352
                        #e4e4e4                        #e5e5e5

                    (2) #454545                  * (3) #444444   Δ: 0.437
                        #454545                        #444444
                                                          #444

Total alike colors: 4 - Average Δ: 2.167 - Total colors: 17 - Distinct colors: 5

Credits

• SupplyHog, Inc - CIEDE2000 Calculations