There is no such thing as a "true RBTA." They are all RBTAs (E. Quadricolor) just different color morphs. Ex: Say a male RBTA with a red oral disk releases his sperm and fertilizes with eggs of a female RBTA that had a green oral disk. Depending on which alleles are dominant and recessive their offspring will produce different phenotypes (external characteristics) depending on how their genetics work (such as incomplete dominance, polymorphism, Codominance etc.). There are so many factors that take into play you just really can't call a color morph of one species true and the others not. There are many races and skin pigments of humans but there isn't a "true human." We are all human just different color morphs per say.