I agree that some irresponsible folks may buy the animals, not thinking about long term care, but they do that with uncolored animals, too. I don't see what's cruel about dying the animals, though. It causes no harm to them.
How can you tell that the animals in the pics are depressed? I've seen the baby chicks, ducks, and rabbits that were colored for Easter, and they didn't seem depressed to me. Do you think it's cruel to dye the animals?