Pure Ameraucana will always have a color/variety specified. A proper breed will know exactly what they have, and will be more than happy to tell you all about them. If a breeder can't tell you what varieties their birds are, they are not breeding actual Ameraucana. They have Easter Eggers. A lot of people order hatchery birds and take the hatcheries at their word that the birds are Ameraucana. When they go to sell offspring, they insist they have purebred Ameraucana. The reality is that they had Easter Eggers the whole time, they just never bothered to learn anything about the Ameraucana breed.
Happens all the time.