Except for the white tiger. I do see lots of paintings of white tigers. Those are not true "wildlife" paintings, however, since white tigers are pretty much non-existent in nature. Almost all white tigers have been bred in captivity.
There are lots of photos of white lions, which actually are found in nature, but I see very few paintings of those.
And what about all the other animals popular in paintings? Why are they never white?
What about a deer? Have you ever seen a painting of a white deer? They do exist in nature either as "piebald", which may be all white or only partially white, or as true albinos. But I've never seen a painting of one.
How about a kangaroo? Have you ever seen a painting of a white kangaroo?