Working in different color spaces

[tebjan]

Is your feature request related to a problem? Please describe.
Working with colors in different color spaces. Nice video and why it can lead to better designs:
https://youtu.be/fv-wlo8yVhk

Describe the solution you'd like
Add the most common color types like XYZ, HSL, and OKLab and more importantly math and blending in these color spaces.
Something like: https://github.com/waacton/Unicolour
The implementation is quite interesting and based on new C# features like records, but it is based on double precision.

Describe alternatives you've considered
Using color conversion nodes everywhere and only using the RGBA as base type.

Additional context
This was planned from the beginning but was never on top of the priority list.