I've had the same color come out with chicks that were from a Blue Orpington rooster over a Buff Orpington hen. I didn't pursue it tho after only one generation.
I've found that extended black (& related colours) X buff (the ones I've used are on wheaten) gives this effect. Extended black cross other colours tends to be, as it is supposed to be, black with leakage. I have thought of reasons why this might be, but don't know how accurate they are.
I've found that extended black (& related colours) X buff (the ones I've used are on wheaten) gives this effect. Extended black cross other colours tends to be, as it is supposed to be, black with leakage. I have thought of reasons why this might be, but don't know how accurate they are.