Credits

color-map builds on published specifications and on other people’s open-source work. This page names each one and says what color-map took from it. The licenses below are the ones each project declares on npm or in its repository, read on 2026-11-02.

No third-party source code is bundled into color-map. It has no runtime dependencies. Where a project below is MIT, BSD, Apache or MPL licensed, color-map uses it as a reference or as a measurement target, not as copied code, so no license notice travels with the package.

Specifications

• CSS Color Module Level 4 and Level 5, by the W3C CSS Working Group. color-map follows them for parsing, the named colors, the conversion matrices in section 19, hue interpolation, none handling, gamut mapping (section 13.2), color-mix(), relative color, light-dark() and contrast-color().
• A perceptual color space for image processing, by Björn Ottosson, the author of OKLab and OKLCH. color-map uses the matrices that CSS Color 4 publishes instead of the ones on that page, because the specification recalculated them for a consistent white point.
• Design Tokens Format Module from the Design Tokens Community Group. toDtcg writes the 2025.10 color value.
• WCAG 2, by the W3C Web Accessibility Initiative, defines the contrast ratio that contrast and the palette builder check.
• APCA, by Myndex. color-map does not include it. The package accepts a contrast function, and the repository’s tests show an APCA recipe that runs through colorjs.io. apca-w3 carries its own license terms, so its code is not copied.

Palettes and scales

• Radix Colors, by the Radix team (MIT). The 12 step purposes, the rule that step 9 is the brand color, and the white-or-dark text rule in onColor follow their documentation and custom palette generator. scaleFromBrand uses one fixed lightness and chroma curve of its own. No Radix scale data is included.
• Material Design 3 and Material Color Utilities (Apache-2.0), by Google. The 13 tones, the dark-mode swap of tone 40 for tone 80 and the role tone assignments follow them. color-map sets tone as CIE L* in OKLCH hue and chroma and does not port the HCT color space.
• Tailwind CSS (MIT). The tailwind-11 scale preset, its 50 to 950 keys and the @theme block that toTailwindTheme writes follow Tailwind v4.

Where color-map started

colormap by bpostlethwaite (MIT) inspired the original createColors and createColorsFromMap, now in color-map/legacy. A legacy test checks that the output matches colormap’s.

Libraries measured on the Compare page

The Compare page reads each project’s documentation and source and runs its published build next to color-map. These projects also taught color-map which APIs and defaults users expect. The page’s method section says how the numbers are produced and where they are weak.

• culori by Dan Burzo and contributors (MIT). A reference for gamut mapping behavior and the benchmark baseline in the repository.
• Color.js by Lea Verou, Chris Lilley and contributors (MIT). A reference for the specification’s edge cases, and the cross-check in color-map’s tests.
• chroma-js by Gregor Aisch (BSD-3-Clause and Apache-2.0). A reference for scale and interpolation APIs.
• @texel/color by Matt DesLauriers (MIT). A reference for a small, OKLCH-focused converter.
• @colordx/core by Dmitrii Kriaklin (MIT). Its approach (a single sRGB representation, a gamut search in linear sRGB and parsing by character code) informed the speedups to color-map’s parsing, gamut mapping and mixing. The Compare page shows the current numbers.
• lightningcss by the Parcel team (MPL-2.0). A native CSS transformer that evaluates color-mix() at build time.
• colord by Vlad Shilov (MIT). A reference for a very small color API.

These libraries are devDependencies of the private color-map-compare package, so they never reach color-map’s published dependencies.

Corrections

Corrections are welcome. Open an issue at cyberuni/color-map if a source is missing or described wrongly.