op-packages/luci-theme-aurora/.dev/tokens/engine.js

import Color from "colorjs.io";

const C = (v) => (v instanceof Color ? v : new Color(v));

// color-mix(in oklab, a p%, b) => position toward b is (1 - p)
export const mix = (a, b, p) =>
  Color.mix(C(a), C(b), 1 - p, { space: "oklab", outputSpace: "oklch" });

export const shade = (a, dl) => {
  const c = C(a).to("oklch");
  c.coords[0] += dl;
  return c;
};

export const set = (a, L, Ch) => {
  const c = C(a).to("oklch");
  c.coords[0] = L;
  c.coords[1] = Ch;
  return c;
};

export const alpha = (a, p) => {
  const c = C(a).to("oklch");
  c.alpha = p;
  return c;
};

export const konst = (s) => C(s).to("oklch");

// Serialize a Color (or string) to an oklch() literal -- no color-mix / var().
export const toOklch = (v) =>
  C(v).to("oklch").toString({ precision: 4, format: "oklch" });