When a dog has colored patches on a white background, called a piebald appearance. The most common colour combinations for the piebald coat are black and white, brindle and white, red and white, blue and white, and fawn and white.
The piebald coat differs from the merle coat in that sense the colour patches are the same shade as the rest of the coat.
Gene
The MITF gene mutation, which results in the s allele on the S locus, is responsible to gives rise this colour.