TIL that cats can be green! If the shades of color in their fur (brown, grey, black, etc) line up just right in their genetics, they will appear as a shade of grey-green in midday sunlight, which is the time of day and lighting used to determine the "canon" color of irl things. Granted, it's super rare, but possible
All this to say that HCWC Doc can and will be green, and now I'm very glad I waited so long to introduce him bc if I designed him yesterday he would've been some shade of brown and I would've been mad today