When is blue not really blue?

[zooplan]

When you say "there must be no yellow or green in the pattern" are you referring to axanthic in reptiles/amphibians?

yes

Are saying I'm hyperxanthic? What did you call me?

That´s what yourself pointed out before yellow (carotins) can turn to red by high density. Furthermore I would call you an albino!

Like most humans are albinos of different types, but those real complete
peoples native in Africa.
Back to the topic I would recommend to search for "Fancy Guppy Breeding genetics". Fisch colour is more like snake colour than mammal colour and Poecilia reticulata might be the best explored specy on earth.