. A Blue Frenchie is one of the most uncommon and sought-after Frenchie hues, thus you don’t see them very often. The hue of blue Frenchies is more silvery or gray than blue. They seem blue because a mutation in the melanophilin genes (MLPH) leads to improper distribution of these cells, causing a diluted coat color and turning pigments that should have been black into silvery or gray.