[Karpattaisp]

A blue coated dog can only have a blue nose. It can be a butterfly or dudly nose where parts are pink but that's not the same as a red nosed dog. It's genetics, nothing to do with standards, just not possible. Just like a blue dog can't have a black nose as their pigment is diluted. Someone may pop in with the markers for coloring and a better explanation, I was terrible at genetics in science class.