Sort of both. I started my project crossing White Leghorns (for production) to Black Ameraucana birds then selecting birds to get back to Black feathering/shanks and blue eggs/pea combs. Someone at the University of Arkansas was doing the same thing already that I didn't know about and for the same purpose! I found out ~1 year into my breeding project I think? I have picked up some University of Arkansas hatching eggs to add the blue diluting gene back to my birds so now I have my project girls + U of A Blue cockerel covering them. Long story short, they are most like U of A blues which isn't a "pure breed" because of how small the breeding population is.