r`, `lch(from lch(0.7 45 30) l c 25deg / alpha)`, `lch(0.7 45 25)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30) l c h / .25)`, `lch(0.7 45 30 / 0.25)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30 / 40%) 25 c h / alpha)`, `lch(25 45 30 / 0.4)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30 / 40%) l 25 h / alpha)`, `lch(0.7 25 30 / 0.4)`);
    test_valid_value(`color`, `lch(from lch(0.7 45 30 / 40%) l c 25 / alpha)`, `lch(0.7 45 25 / 0.4)`);
    test_valid_value(`color`, `lch(f