The APCA version, to be licensed for use with guidelines: W3/AGWG.

Learn about accessible button contrast then generate your own accessible button color palette

Contrast-Finder finds correct color contrasts (background / foreground) for web accessibility (a11y, WCAG, RGAA). https://app.contrast-finder.org

Firefox extension to ease use of Asqatasun Contrast-Finder

For a given color, find a contrasting color (not optimal).

Docker Maven for Asqatasun and Contrast-Finder

Javascript modules to find field of vision and visible contrast of the visually impaired cutting the cost of expensive machines