oklch color notation support (and better fallback behavior)

[lediur]

Hi, thanks for creating this library!

I noticed that there's currently no official support for oklch color notation, since the underlying https://github.com/Qix-/color dependency library doesn't support it yet.

When I try to use oklch to describe a color value on a theme property, it causes other themes to not wrap the property value with rgb(), even if their value for the property is using a color notation supported by the dependency library.

See https://codesandbox.io/p/devbox/flamboyant-satoshi-zgz3fz for an example.

Is there a way to work around this, or do I need to fully switch to using or not using oklch?