Sorry the Am-leghorn produced green; I would have expected blues also. I have been thinking of getting barred leghorns to cross with my black Am to produce large blue eggs. DM suggested it and a Am breeder suggested it as well.
I'm finding egg colors more complicated than it originally seemed to be. I have two lines of AM boys: one more of a green egg because his sisters laid more green than blue; and another line that should be more blue than green. I have looked at the AM card for egg color and the colors are an array of about 50 shades. from grays, to greens, to blues , and in betweens.
Late last summer I picked up ONE brown-chocolate egg-- looked like a huge NECO wafer in an egg- shape, that pastel powdery tan-brown. I have kept it. Only got one. ( I've lost a couple hens--perhaps one of those laid that egg.) Intriguing colors.