Palette distinguishability

Check whether every pair in a palette stays apart under a given color vision deficiency.

const report = swatch.checkPalette(
	["#e41a1c", "#377eb8", "#4daf4a", "#984ea3", "#ff7f00"],
	{ cvd: "deutan", minDeltaE: 11 }
);

report.safe;        // false
report.minDeltaE;   // e.g. 7.2
report.unsafe;      // [{ i, j, deltaE, safe: false }, …]

Options

Nudging a single color

Walk a color's lightness until it clears a threshold against a reference, preserving hue and chroma:

swatch.nearestDistinguishable("#ff6666", "#ff0000", {
	cvd: "deutan",
	minDeltaE: 15
});

The §12 panel of the playground wires both calls together — paste a palette and click nudge on any unsafe pair.