Danes come in six acceptable colours: Fawn, Brindle, Black, Blue, Boston (Mantle), and Harlequin.
Fawn: a golden yellow with a black mask on the face
Brindle: golden base coat with defined black striped laid over as chevrons (almost tiger-striped appearance)
Black: Solid black coloured dog
Blue: a steel grey solid colour
Boston/Mantle: this pattern is best described as marked like a penguin, must have a white tail tip or is not considered a true Boston
Harlequin: a white dane with torn black patches distributed over the body.
For more details please go to the breed standard.
These colours are acceptable to show in conformation for a Canadian championship. A mismarked dane can be born in a litter and they are registrable as they are purebred, from registered parents but a mismark is a colour not acceptable for competition in conformation (ie. merle, harlequins with too much black, blacks with large white spots on their body, brindles with little or no fawn base colour, etc.). Aside from the colour, mismarked colored Danes still can preform in functions sanctioned by the Canadian Kennel Club, just not in conformation (dog shows). They are as equally wonderful a pet as a conformation-marked dane.
Caveat: Don’t be fooled – there are no ‘rare’ coloured Great Danes. Don’t walk, run from any breeder claiming to have a ‘rare’ coloured Dane.