Robert Kaleski, who wrote the first standard for the breed, was influential in its development. Robert Kaleski, who wrote the first standard for the breed, was influential in its development. There are two accepted coat colours, red and blue. Chocolate and cream are considered to be faults. Blue dogs can be blue, blue mottled, or blue speckled with tan on the legs and chest and white markings and a black patch or 'mask' on one or both sides of the head. The distinctive adult colouration is the result of black or red hairs closely interspersed through a predominantly white coat. This is not merle colouration (a speckled effect that has associated health issues), but rather the result of the ticking gene. A number of breeds show ticking, which is the presence of colour through white areas, though the overall effect depends on other genes that will modify the size, shape and density of the ticking.