Hello!
Sorry you haven't received replies yet. When I got my first glider I was told by the breeder that as they get older, their fur changes colors. I don't think it's diet related but I'm not positive. I wish I had of asked the breeder. I just assumed it was part of growing and maturing. If you do change diets, HPW and BML are really good ones so you might feel more secure with one of those.