Problem

Since#24619pcolormesh can handle RGB(A) arrays. There is an entirely reasonable request in Cartopy thatpcolormesh there also supports this (SciTools/cartopy#2156). However, Cartopy’s wrapping logic forpcolormesh actuallyusespcolor under the hood, so we’d need RGB(A) support inpcolor before we could get it working.

Proposed solution

I think we first need#25027 and then add RGB(A) logic on top of that, but I have not dug too far into the details.

cc@greglucas