I realized I couldn’t think of a single green mammal so I DDG’d it and it’s true. In a nutshell, the pigments that give mammals their colors are limited to warm colors (so no blue or green) and you could also fake a green color by reflecting mostly just green light off you (it’s how birds do it) but it seems to be something only feathers and scales are good at, not fur.
I realized I couldn’t think of a single green mammal so I DDG’d it and it’s true. In a nutshell, the pigments that give mammals their colors are limited to warm colors (so no blue or green) and you could also fake a green color by reflecting mostly just green light off you (it’s how birds do it) but it seems to be something only feathers and scales are good at, not fur.