I think how big they were when they changed would be a good question. With good genetics and great feeding you could have had them 500 grams in a few months.

Forget the name of that really quick change axanthic line associated with some albino projects. Last I read it had been determined to be a 2nd gene and not really a line of albino as some had thought. It's just that it shows up better in the snow looking albino hatchlings but can also be seen in axanthic looking non albino siblings. But it seems to change very very quickly, like in a shed or two. Interestingly the double homozygous albino + whatever this is called babies that start out snow looking grow into really nice looking adult albinos. I can't seem to find the old thread on this but think they are the albinos that turn out orange on yellow with no white which is a bit ironic for something that started out axanthic looking.

At any rate, whatever that axanthic gene is called it changes so fast it doesn’t seem like it could be what you have here. Perhaps this is a new line altogether.