As I understand it probably the white bird is black under the white gene... and now all chicks carry a recessive white gene. So if you cross back to white parent you could get white, black, or blue (if you use blue offspring), cross the f1s all three colors possible but if to blue parent, you...
Birches might be it check out these Pekin Blue Birchen... Bobtail could be same basic genetics minus the lacing? And maybe something that dilutes the males more?
There are several breeds with white heads, and black barring or even black bodies like the Polish... could be a gene like that at work, in conjunction with lav. and maybe other modifiers?
Oh wow stunning... I see from the paper in 2013 they planned to do more test breedings, I have not found the results yet. This could be a bunch of genes at work, first you got something that knocks out neck color, there must be a sexlinked factor I would think. I found a new breeds article for...