Like the Chow Chow, the Shar Pei also has a black tongue. The color varies between purple and deep dark gray blue that looks almost black. In both breeds it is part of the breeds standard. Blue tongues can also be found in other South Chinese breeds, but not as standardized as in the Shar Pei and Chow Chow. Why the dogs have a black tongue has not yet been clarified.
Pigment spots on the tongue, however, occur in many breeds and do not mean that they are mixed breeds.