Sorry I didn't read your edit on colors. Only about the history. Which does seem unimportant if bulldogs and pit bulldogs split from EM predecessors, what was worded in the OP post was different though which was that were mixing a bunch of dogs. So what do you mean by a "true brindle"? A brindle is brindle it is the same gene be it mastiff, bulldog, greyhound or dutch shepherd. It is caused by what you said Kbr allele. I never mention albino, genes for such a condition hasn't been isolated in dogs (to date anyway). Since I see you put that in edit. I already explained how white is absent of pigment and I was talking about white found on S Locus (doesn't exist on A Locus).