Blue Brown
Blue brown is a difficult to breed and therefore seldom occurring colour. It is the same as the brown, except that any black is replaced by blue. The golden and yellow parts become lighter in colour too due to the dilution of black into blue. It is not easy to obtain beautifully uniform blue parts in these specimens, as there often is some white or black. It’s a huge challenge for the persevering fancier. The hens often miss the background colour on the back. In such a case, the back will appear rather uniformly blue. If we try to imagine how such a specimen would look in the regular brown variety, we would see that the back would be black. One could call it some sort of blue smut. Especially in the blue brown variety one shall have to breed with cocks having a very weak blue pattern on the neck hackle.
The blue brown colour is not homozygous. By mating a blue brown cock to a blue brown hen the offspring will be about 50% blue brown, 25% brown and the last 25% pile. By crossing a brown to the resulting pile specimens, the offspring will be 100% blue brown .