Aulonocara stuartgranti 'regal blue' would be a little more accurate. Wild populations at different locations vary and I've seen stuartgranti from more than one location called 'regal blue'. Ideally you'd have A. stuartgranti + location. When they come from importers or careful breeders of imported stock (or stock of specific provenance) you'd expect to see something like Aulonocara stuartgranti mbenji, or cobue blue, or a similar further identification. Often, however, the truth is you can't count on peacocks to be pure to an original location or even necessarily pure to a species, since peacocks will notoriously hybridize if steps aren't taken to prevent it and maintain a pure strain. "Mixed peacocks" would certainly be suspect in this regard.
Essentially, a first step to getting peacocks as they're found in the lake (if that's a goal) is to look for Aulonocara + species + location rather than relying on common names, or made up names like 'dragon blood'. Getting a true, native Aulonocara generally means an importer, trustworthy breeder who can document their stock, or possibly a higher end fish shop (a vanishing breed, it seems).
Not knocking your fish, it's just a reality in the hobby, like all the designer (man made) peacocks available these days. Also to help you be more knowledgeable about Aulonocara (peacocks) and a bit of how to find pure types if that's your goal.