yellow tang not looking too yellow

Hey all, hope someone out there can help me with this. I just picked up another tank and all it's contents, included are a dogfaced puffer, a pair of blue hippo tangs, and a yellow tang. From everything that I can find on the internet, and every yellow tang that I've ever seen, they are supposed to be a very bright/deep yellow. This tang is more of a pale yellow, almost white in colour or like a cream colour, it's fins are bright yellow, and it has a stripe down it's side that is also yellow, but the rest of the fish looks very light in colour. Does anyone know why this fish would be this colour? What may have caused it? Can I get it's deep yellow colour back? Any help would be greatly appreciated. Thanks

Could be the stress of the move, poor diet with the previous owner, tank aggression at the old or new home....or it might just be the colour he has always been.

i use to have a yellow tang, and when it was stressed the line on its side would turn white, the line on this one seem pretty yellow still.... but im am no expert