Mumbles, my lionhead bunny, has a new darker spot on his back. I don't remember it being there before. I've looked at him closer, and there doesn't seem to be any kind of wound or anything. He'll be a year old next month.
Tippy was solid white when I got her. A six months later, she was gray, brown, and white. Now she's gray with white patches, a year after that. So..yeah, normal!