Are there any green mamals?

Green seems like one of the camouflage colors that should have evolved for some mammal somewhere on earth. There are lots and lots of green birds, reptiles, fish, insects, etc... It's not like there are climates or environments that other animals have adapted to that mammals haven't... there are polar mammals, aquatic mammals, underground mammals, desert mammals, jungle mammals, flying mammals, etc... Mammals are VERY adaptable... So why haven't any mammals ever evolved green camouflage? Just wondering.