Any dog can be blue, however, it 'can be' a fault in conformation. There were a few 'blue' gamebred dogs back in the day.
Because of the big bully movement where most dogs are 'blue'.. the myth of "Pit bulls aren't blue" started.
I think there was a blue or dark gray gamebred dog that won ADBA. I am trying to remember the name of the owner who is a female.
This is from ADBA:
back when head is in a normal upright position.
1. Dog is socialized, showing interest in things around him.
2. Although some degree of dog/animal aggressiveness is characteristic of the breed, unruly behavior will detract from the judges ability to accurately judge an individual dog’s conformation.
1. The vitality of the dog’s spirit, the gloss of the dogs coat and the sharpness of the dog’s eye, will exude the healthfulness of the individual animal.
2. Colors or color patterns known to be genetically linked to health problems will be considered a serious fault. Major faults: merle color pattern, albinism (white dog with blue or pink eyes, pink nose, lips, no pigment present on pads, rims of eyes etc.)
I am not disagreeing, just sharing some factual info for others.
I 100 % agree that "Everything is not a pit bull!"