Compatibility with l3color module of LaTeX3

[callegar]

Named colors defined with the interfaces in the l3color module of LaTeX3 are not usable with xcolor.

See for instance https://tex.stackexchange.com/questions/682078/l3colors-colors-unusable-with-tikz

Would be useful if xcolor could also check named colors defined with the l3color module.

[josephwright]

We know :)

[callegar]

I supposed so, but not seeing the issue here, I thought that in any case users would have benefited from having the issue tracked here.