safepalette

Colorblind-safe color palettes — generate, check, and fix. Ask for N safe colors, test a palette you already have, or repair one that fails — for protanopia, deuteranopia, and tritanopia.

npm install safepalette

const sp = require("safepalette");

sp.generate(5);                          // 5 colorblind-safe hex colors (Okabe-Ito based)
sp.isSafe(["#d7191c", "#1a9641"]);       // false — red & green collapse under deutan/protan
sp.fix(["#d7191c", "#1a9641"]).colors;   // a safe palette near the originals
sp.OKABE_ITO;                            // the canonical 8-color safe palette

API

• generate(n, opts?) → up to n colorblind-safe hex colors. n <= 8 is the Okabe–Ito palette (safe by design); above 8 it extends only with colors that keep the whole set passing. Because mutually-distinct-under-CVD colors are finite, very large n may return fewer than n — it never returns an unsafe one.
• isSafe(colors, opts?) → true/false for the whole palette.
• fix(colors, opts?) → { colors, drift, pass, residual } — an adjusted palette that passes, separated along lightness, staying near the originals.
• check(colors, opts?) → the full per-type conflict report.

How it decides

The safety test and the repair are opticquiz-cvd's checkPalette and fixPalette — Machado, Oliveira & Fernandes (2009) simulation + CIEDE2000, open access: https://doi.org/10.5281/zenodo.21310578 . The generator is seeded with the Okabe–Ito safe palette (Wong, Nature Methods, 2011). No colorimetry is reimplemented here.

Not a legal audit

A screening/design aid for the color-distinguishability axis, not a WCAG/ADA audit.

Licence

MIT.