After reading about this, it occurred to me that in the beginning, buff orps and the blacks shared no common ancestors. Today I doubt that's true but it is interesting. I'm thinking since the blues and lavenders have non-orps closer related than the blacks that aren't related to them and the buffs, maybe there is, in a limited way, a difference in their laying. Being not orp wouldnt' have anything to do with it most likely, but breeding for color alone might.