// Darken RGB by fraction (from 0 to 1).
export default (r: number, g: number, b: number, fraction: number) =>
  [
    Math.max(0, Math.round(r - 255 * fraction)),
    Math.max(0, Math.round(g - 255 * fraction)),
    Math.max(0, Math.round(b - 255 * fraction)),
  ] as const;