In #7948 we resolved that gradients should interpolate in oklab by default. This introduces an inconsistency between gradients and color-mix(), since the latter requires an interpolation space. At the time we did not want to introduce a default, but I think we’re now confident enough that OkLab would be a good default. Not only does having to type an interpolation method every time make color-mix() tedious to use (tediosity that is multiplied when it’s nested), but also most authors don’t really understand color spaces, and tend to use in srgb as that’s familiar, which produces the worst interpolation they could possibly get.