Support relative color expressions

[doup]

It looks like relative colors are not supported. I'm getting the following error in a Zola project when using them:

Error: Error: Only 3 elements allowed, but 5 were passed.
    ╷
151 │     color: hsl(from var(--search-category-bg-color) h s 90);
    │            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ╵

These should be ignored as sass-lang.com does. For anyone looking for a workaround, unquote can be used to appease the compiler:

color: unquote("hsl(from var(--search-category-bg-color) h s 90)");

Thanks!