Do rats change colors often? (DUW)

[satomi325]

Awww she's cute!! I think they do, my male rat was a solid smokey gray color when he was a pup, now that he's a fat adult rat, he's more of a salt and pepper color, a lot more white in his fur than when he was a baby

Thanks!
I was just wondering because the rest of my rats haven't really changed and they're all about the same age.