Hello,
I am an aviculturist and though I no longer breed GCCs I still share my life with them.
all of the mutations (as they are revered to in the USA) are naturally occurring in the wild. However, because in the wild a flock usually turns on and kills birds with unique coloring, it is only in captivity that we see the extreme variety.
Because the initial developers of the new mutations (many of which have come from Feather Tree Aviaries) were very careful to cross out the bloodlines to normal green birds and minimize inbreeding, our GCC population is extremely uniform in health. There is absolutely no risk from getting a different colored bird, at least in the USA. I have noticed however that turquoises tend to be slightly larger sometimes.
As for personality there is also no difference. Some small time breeders claim that there is a difference but this stems not from the birds bring a certain color, but from the breeder having mostly related birds in a certain color. His or her LINE of cinnamons may be more friendly, etc, but it does not apply to the mutation at large.
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