function rgbaToLcha(color) {
  const r = a1(color[0]);
  const g = a1(color[1]);
  const b = a1(color[2]);
  const y = a2(r * 0.222488403 + g * 0.716873169 + b * 0.06060791);
  const l = 500 * (a2(r * 0.452247074 + g * 0.399439023 + b * 0.148375274) - y);
  const q = 200 * (y - a2(r * 0.016863605 + g * 0.117638439 + b * 0.865350722));
  const h = Math.atan2(q, l) * (180 / Math.PI);
  return [
    116 * y - 16,
    Math.sqrt(l * l + q * q),
    h < 0 ? h + 360 : h,
    color[3],
  ];
}
@param {Color} color RGBA color.
@return {Color} LCHuv color with alpha.