My first bun, was white with gray ears and tail that got lighter in the winter and darker in the summer. She also got a light gray streak down her back which vanished in winter.
Shadow has turned into a different bunny. He started out dark gray with darker face, ears, tail and legs with tan toes. He is now 6 months and is a silver grey with a dark mask. Only the ears and tail remained dark gray. At one point, he developed 2 light gray marks on his rump in the shape of question marks. They have now vanished. Even though he is a short haired bun, he went through a period when he looked down right scruffy with all the varied patches. I went crazy trying to brush tuffs out, but it was all optical illusions.
Basically from above he looks like he is wearing a silver suit with his head, feet and hands sticking out the sleeves. As for where all the hair is going to, who knows. I brush him and not a whole lot comes off him.