Is he for breeding or is he a pet?
If he is for breeding: At 7 months now in December, that means that when you got him in July he was only 3 months old. 3 months is too young to evaluate a chinchilla as they have not yet gone through their first prime and are not showing all their genetic potential. When buying a young chinchilla, it is always a waiting game to see how they turn out once they reach adulthood... and a bit of a risk. This is one of the reasons I only buy adult chinchillas for breeding. Young chins can change so much, you don't know if they will end up looking better, if they'll stay the same, or if they will get worse. I do have many chins from Gary and they are all beautiful animals but then again, I was able to choose them when they were adults. Even my chins from my best pairings, sometimes you'll get one kit in the litter that, as an adult, surpasses the quality of their parents and the other kit that just didn't take on all the good qualities of the parents... but you just have to wait and see how they turn out before making any breeding decisions. You may want to take him to a show this winter season to see how he does.
If he is a pet: I wouldn't worry about it! He is a cutie no matter what and his fur doesn't contribute to his personality!