It is not, but argyllcms is. See this excellent post on github for more insight. Also the next post by the same user. I linked it elsewhere here on pixls but its almost impossible to find anything reliable thanks to lots of “opinion posts” half-baked advice and people trying to bump their post counter to new heights without adding to the discussion.
I’m in the same boat. As of now it seems like loading and applying color profiles under wayland works but its by no means reliable or “complete” in any way. Darktable can detect an installed display profile for example but what you see in darktable might not match what you see in other applications. It’s all a big mess for now with people testing stuff and trying to find workarounds.
Here is what I ran into recently, using darktable in conjunction with gnome/wayland and a profile created with DisplayCAL in windows.