Changes in color of fur!

Question
Hello my name is Mesha I'm wanting to ask you a Question,
I have owned my rat Templeton (Big Boy) for about almost a year, about a couple of weeks ago, I noticed that His Fur is becoming a silver like color, his fur originally is a dark Grey, I was thinking it could be due to the changing of weather... What do you think? Should I be concerned?!

Answer
First, have him checked out at the vet for external and internal parasites, as that is the most common source of color change. Also be sure that your diet (what you primarily feed him) is complete and total, and he's getting the nutrition he needs. If you can rule that out, its probably normal coat change and I wouldn't worry about it.