But then it would be considered a red Easter Egger, not an Ameraucana.
It can work the same for some breeds of horses. You can cross a Standardbred mare and a Standardbred stallion and if you got a colt that can't trot a mile in 2:30, it couldn't be considered a Standardbred. You can cross two registered Rocky Mountain Horses and if the foal doesn't have proper breed characteristics (someone actually comes and checks) then the foal can't be registered. Those are decisions made at the level of the breed association that issues the registrations.
For good or bad the Ameraucana Breeders Association has decided that Ameraucanas only come in certain colors, and if they aren't those colors, they aren't Ameraucanas. If you think that's wrong, then your best bet is to get on the board of the Association and change the rule. In the meantime, non-standard colors of Ameraucanas are considered Easter Eggers.
Ok i changed my mind about not expressing opinon. I compltley agree with you.