anerythristic and axanthic are NOT one and the same gene.In simple terms erythopores produce red pigment,erythristic pretains to red,anerythristic pretains to no red.Xanthophores produce yellow pigment,xanthic pretains to yellow pigment,axanthic pretains to no yellow pigment.Once you know this info. then it is very understandable that anerythristic and axanthic are NOT one and the same gene under any circumstances.Yes the two terms can be used interchangably but that would incorrect.There is no confusion once the equation is understood.A mostly yellow snake{axanthic}that is incorrect, a mostly yellow snake would be termed {xanthic},a mostly red snake{anery.}that is incorrect,a mostly red snake would be termed {erythristic}.There is no problem in yellows and reds in brooksi,if the snake in question shows reds,those reds come from erythophores,if the snake shows yellows,those yellows come from xanthophores,but no way can reds come from xanthophores or yellows come from erythophores.