`, `lch(from lch(0.7 45 30 / 40%) 50 120 -400deg / -500)`, `lch(50 120 320 / 0)`);

    // Testing valid permutation (types match).
    // NOTE: 'c' is a vaild hue, as hue is <angle>|<number>.
    test_valid_value(`color`, `lch(from lch(.7 45 30) l c c / alpha)`, `lch(0.7 45 45)`);
    test_valid_value(`color`, `lch(from lch(.7 45 30 / 40%) l c c / alpha)`, `lch(0.7 45 45 / 0.4)`);

    // Testing with calc().
    test_valid_value(`color`, `lch(from lch(0.7 45 30) calc(l) calc(c) calc(h))`, `lch(0.7 45 30)`