Okay, I lied. I'm back in.
If we really want to be snarky about it, then by definition blue AMs aren't a true ameraucana since they don't breed true either. Blue to blue gives me blue, black or splash out of that mating.
I buy your definition of breed IF, and only if, each color of ameraucana is considered its own breed. Otherwise the breed is the conformation (shape and form of the bird, leg type, comb type, etc) and egg color. We are back to semantics again.
To say that blues and whites and buffs and blacks and splash and wheaten and blue wheaten are ALL ameraucanas does not make sense by your definition because if I mix the colors they do not breed true. To say that wheaten ameraucanas are a breed and white ameraucanas are a different breed (etc, etc and so forth) makes sense then, because I only get them to breed true within their color line.
It does not work, however, to call all of the colors the same breed. This has been my argument all along. Either the ameraucana standard is about shape, form and egg color (with the feather color being a different issue applicable only to showing) or each color has to be categorized as a seperate breed. It does go back to A x A= A
Wheaten AM x Wheaten AM = Wheaten AM
I get that and totally agree if we consider that wheaten AM is a definitive breed. But if we are only using color as a modifier and not a breed, then the old AM x AM= AM statement has to be true. To say otherwise is to defy logic.