You know even PURE Ams egg color will vary. They have a pretty extensive color chart. I have had pure ams from top breeders in the country and egg color will vary from blue to green.
I gotta agree with this... had a couple convos recently with 2 different major breeders... one still gets some greenish eggs he is trying to weed out and the other still gets white egg layers due to not all of them carrying 2 blue egg genes...
Heck, I've got EE's that lay prettier blues than a lot of my Am's, lol...