How rare is a red Rottweiler?

The percentage of rottweilers that are red is unknown. The color used to be incredibly rare in purebred rottweilers. However, The Rested Dog Inn states that certain breeders have inbred the dogs to increase the prevalence of the color in their litters.

A Love of Rottweilers reports that many rottweiler experts believe that some or most of the red rottweilers offered for sale are actually mixed-breed dogs rather than purebred rottweilers. Big Sky Rottweiler Rescue agrees, stating that red rottweilers offered for sale are either the result of heavy inbreeding or are mixed-breed dogs being passed off as purebreds. The rottweiler standard does not allow for any colors other than black and tan.