Erythriphores in ball pythons discussion

[PythonWallace]

I have never been under the impression that balls lack red pigment.

I was always under that impression, but I don't remember why. Am I just wrong here? Is it common acceptance that ball pythons have erythriphor? If so why don't we ever see people selectively breeding for high red balls like we see for high yellow, or high contrast red snows? I would also think that an olive green project would be named an anery project if this was common knowledge. If this is the case, sorry for starting this thread, but at least I might learn some things. Please post your opinions or knowledge for me.