import math


def xyz_to_lab(xyz, reference=(95.047, 100.0, 108.883)):
    """Convert CIE-XYZ color to CIE-Lab."""
    delta = 6 / 29
    f = [xyz[k] / reference[k] for k in range(3)]
    x, y, z = [math.pow(t, 1 / 3) if t > math.pow(delta, 3)
               else (t / (3 * delta * delta) + 4 / 29)
               for t in f]
    return (116 * y - 16, 500 * (x - y), 200 * (y - z))