Bristlenose going yellow?

Hello all,
I have a couple of juvenile 'normal' bristlenose (out of 30+) which are about a year old and their lips & front of their pectoral fins are going yellow!!!
Hopefully it's not a disease of some type...any ideas?
They seem quite healthy
They are in a large tank (330 litres) with 8 small to medium size goldfish. They have been in this environment since hatching.
Are they going albino...or are albinos hatched white?
Many thanks,
Cheers...Singo

How many Bristlenose in a tank?

How many Bristlenose should I keep in a 330 litre tank with 8 small to medium size goldfish?
Put another way, what volume of water should 1 BN be kept in?
Many thanks

i have had bn colour morph on me but their eyes stay same colour... had an albino suddenly start changing to a common..... and had commons develop albino patches but never went full albino body colour... after a few months they changed back to mostly common b/n colouring...

as for how many b/n per water volume... cant have too many IMO as long as your filtration keeps up with the waste all your fish produce and you dont get ammonia spikes etc....

Thank you very much for your advice