Pitbull" is not a breed. American Pit Bull Terrier, American Staffordshire Terrier, and the Staffordshire Bull Terrier are the breeds that are generally called pit bulls. rednose pits or blue pits are terms back yard breeders make up to con people out of more money for their pups. these are only colors.
Ignore the top comment, when people say "pit bull" they mean the American Pit Bull Terrier, however over many years the term pit bull have been used to describe any breed that look like the real pit bulls. These are uneducated people. Pit bulls come in all colors, red, blue, black, white, chocolate, etc. Because pit bulls were originally bred for what they could do not color. But over years idiots got their hands on the breed, and only bred for color, head size, etc. That completely destroys the pit bull and what they were originally bred to do. So when you see someone advertising, blue pit bulls or red pit bulls, with big heads and wide chest. DON'T buy these dogs, these people just want your money and don't care for the dog. Never get a dog for looks but for what they can do. And besides these dogs are usually unhealthy since they have been bred to dogs of the same color over, and over again, which leads to genetic problems.