here is my common GF he was bought as a 1" feeder fish 6-7 years ago for £1 he is now approx 8" long and really chunky. we started off with a tiny 18" tank for him and he is now in a 3ft and i think he will need a bigger one soon!!
excuse the algae on the glass!!!

Has he always been white, or does the colour change as they get older ??

no he started off as a total orange goldfish, then when we moved him to a 2ft tank he changed to white within a week!! and it was also around that time he got his breeding tubercles on his gill covers (white spots that only boy goldfish have). i do know that lots of goldfish change color as they mature.

Welcome aboard 007IRON!
I have lots of common and comet goldfish too.