To simplify things for you. To be considered a true Ameraucana it has to lay blue eggs, have a pea comb, white skin, both a beard and a muff, and slate blue (or blackish) legs. If it lays any color of egg other than blue, or if it has any type of comb other than a pea comb, or if its skin is any color other than white, or if it lacks either a muff or a beard, or if it has any color of legs other than slate blue (or blackish), it is an Easter Egger and not a true Ameraucana. I hope this helps.)
Sort of. They also have to be one of the 8 colors recognized as true breeds.