This is interesting stuff. Im going to be making a pen with a splash plymouth rock roo and some splash plymouth rock hens. Both were the product of blue x blue. Thats why I was wondering if a second or third generation would change into maybe the bird being completely white without the blue feathers. If introducing black, that would result in blue birds, and Im not sure how that would help the splash coloring.
I am growing out some blue plymouth rock chicks that are a cross of a blue roo and barred hens, and the lacing is just gorgeous. I was thinking it was the barring gene doing that, but perhaps it is indeed the black from the barred hens. Im also going to put my splash roo in with some barred hens to see what coloring I get; obviously I know I will get all blue, but I want to see if the splash will give a light blue and the barred hens contribute the lacing.