code: function cielabToXYZ ({ l, a, b, alpha }) {
      // Wikipedia: http://en.wikipedia.org/wiki/Lab_color_space
  
      const f = t =>
          ((t >= 0.206896551724137931)
              ? ((t) * (t) * (t)) : (108.0 / 841.0) * ((t) - (4.0 / 29.0)));
  
      return {
          x: WHITEPOINT_D65_X * f((l + 16) / 116 + a / 500),
          y: WHITEPOINT_D65_Y * f((l + 16) / 116),
          z: WHITEPOINT_D65_Z * f((l + 16) / 116 - b / 200),
          a: alpha
      };
  }
docs: Convert CIE L*a*b* (CIELAB) to CIE XYZ with the D65 white point