def test_luminance():
black = luminance((0, 0, 0))
blue = luminance((0, 0, 255))
red = luminance((255, 0, 0))
green = luminance((0, 255, 0))
yellow = luminance((255, 255, 0))
cyan = luminance((0, 255, 255))
magenta = luminance((255, 0, 255))
white = luminance((255, 255, 255))
assert black == 0.0
assert white == 1.0
assert black < blue < red < magenta < green < cyan < yellow < white
def is_dark_color(color: Color, dark: float = 0.2) -> bool:
luma = luminance(hex_to_rgb(color))
return luma <= dark
def luminance(self) -> float:
""" Returns perceived color luminance in range [0, 1] from dark to light.
"""
return luminance(self.rgb)