if your goldfish are 8 months old they can not be called fry anymore. they should already show the head-growth and should be displaying their colours and they definitely would have outgrown a 10 gallon tank considering their high-protein diet. if your information is correct then i can only conclude that they are not red oranda and you have been misled.

there could also be another possibility. not all the fry from a spawning of red oranda will be red and oranda specially if the fish does not have a good pedigree. some breeders who are into it for the money dont care about quality.. i have seen a breeder whos method was to put in sevral varieties of goldfish in one big spawning pond. later on he would just sort the resulting mix by size and shape. if you happened to breed a pair of his "red orandas" there was no telling what breed you would get
aside from that, orandas occasionally do give birth to non orandas

HI

That doesn't really help the situation much...

Goldfish fry can start to change color from a few weeks of age but also take a couple of years to start changing.  There are factors which influence this,  genetics, temperature and sunlight (or artificial light) I have bred goldfish in spring which have started to change color after about 5 weeks of age.  I have then spawned the same parent fish again towards the end of Summer and had nothing change color until the following Spring.   If you put a heater in your tank at the lowest setting and have a light above then changes should begin. As for orandas I myself have bred with breeders which themselves took over a year to change colorbecause the fish was very good quality in all other areas, thetrick is to cross it with a fish known for producing fry which change color early.