So if you mate a blue with a blue you have a good chance of having a full litter of blues. However something to keep in mind that the red gene is recessive in the blue coat so even if you do mate two blues you can still get reds. I just bread my 1/2 blue 1/2 red bitch with a blue male and got all blue pups. Kind of luck of the draw especially when it comes to the blue coats.
A blue pit bull is quite simply one with a "blue" coat which can range anywhere from a light silvery gray to deep charcoal. Likewise, blue nose pit bulls have grayish nose leather rather than the more common black nose. Blue pit bulls ARE NOT a separate breed or a distinct bloodline of the APBT. What causes the blue-gray coloration may actually surprise you. Blue is a dilution of the color black. The genetic make-up of a blue dog contains a recessive trait that causes the color pigmentation to clump around the middle of the hair shaft leaving the tips colorless.
You may recall from your school days in science class that in order for a recessive trait (like blue eyes in humans) to be expressed in the offspring, both parents must carry the gene for the recessive trait. Add to that the fact that the alleles that interact with and influence coat and skin color and color patterns are found in several places along the canine genome, and you can appreciate how tricky producing a particular color can be
