A male guppy tail that changes colors? When I first got my male in April, something had nipped at his tail for some time. There was barely anything left. I felt so bad for him which is why he was chosen. His tail is growing back and he is a beautiful yellow color. He recently started getting some black along the top. However, sometimes it is a bold dark black and other times it looks gray and almost translucent. Has anyone else ever seen anything like this?