The color of egg an offspring lays from a pair is very dependent on what color egg the father hatched out of. If he was hatched from a blue egg, he will contribute the blue egg gene to his daughter and she would lay a green egg (if hatched from a brown egg laying mother). It doesn't matter is he's pure Ameraucana or not, as many Ameraucana have faulty green eggs. If he hatched out of a green egg, he could contribute a blue or brown eggs gene to his offspring. Matched to a brown laying hen, could produce either green or brown egg laying daughters.