The blue gene is an inhibitor of black that can stack in potency. There is a mirror location of each gene so a bird can have nothing in a genes location or one gene or two copies.
Blue color is the expression of a bird carrying one copy of the blue gene. It's a black bird who's color has been diluted due to that gene. Two copies dilutes black to white with splashes of blue feathers. Hence the name.
The resulting black birds carry nothing forward in regards to the blue gene but do carry the lace gene that should be in all blue varieties. Blue birds mated to blue, each carry one copy, results in 50% chance of offspring carrying only one copy-blue, 25% chance of carrying two-splash, and 25% chance of having none- black. The three colors of a blue variety flock.
The standard shade of blue should be pigeon. The shade can range from near black to near splash. This is why you should not mate black to splash all the time. People do to obtain 100% blue chicks that sell for more but there is no way to control the resulting shade of blue. It will run wild the full range of color. A blue bird should be in every pairing and even better is both parents being blue. This way a flock can obtain a much more uniform look with the owner making choices as to which shade of pigeon blue they prefer. A little lighter or darker is personal preference. After multiple generations the blue will fade without an introduction of black. It's a balancing act to maintain proper hue of blue in a flock.
I'll run out and snap a photo of my Blue Laced Red Wyandotte for you...BRB
Her parents were both blue! She has a sister that is black from the same parents!
