 `lch(from lch(0.7 45 30) 0 0 0deg)`, `lch(0 0 0)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30) 0 0 0 / 0)`, `lch(0 0 0 / 0)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30) 0 0 0deg / 0)`, `lch(0 0 0 / 0)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30) 0 c h / alpha)`, `lch(0 45 30)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30) l 0 h / alpha)`, `lch(0.7 0 30)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30) l c 0 / alpha)`, `lch(0.7 45 0)`);
    test_vali