.color-functions {
$color: red;
hue: hue($color);
hue-type: type-of(hue($color));
hue-unit: unit(hue($color));
hue-comparable: comparable(hue($color), hue($color));
x: comparable(10fu, 10fu);
x: comparable(10px, 10px);
x: comparable(10, 10);
y: type-of(10px);
y: type-of(10deg);
z: lightness(red);
z: type-of(lightness(red));
z: type-of(50%);
z: comparable(lightness(red), 50%);
}