The phaeomelanin pigment plays a significant role in bringing in the red coloration in dogs. Red is also one of the standard coat colors of the Cairn terrier, and so are its variations like red wheaten and red brindle.
Red Brindle
They have a red body with a combination of brown or black, resulting in a brindled pattern.
Red Wheaten
The red wheaten Cairn terrier has a reddish coat with patterns of yellow over it.
