This post features several Mastiff puppies, each with different color coat and this is what we have learned about why they look so different even though they are all pedigreed Mastiffs. Our perspective as hobbyists is that coat color inheritance is not necessarily limited to breed or even to the canine species.
We have read about blue brindle Mastiffs, black Mastiffs, Mastiffs with white blaze, blue masks along with other color variations in historical publications. Between 1883 and 1916 there were Mastiffs registered with the AKC as Blue Brindle, Black and Tan, Cream, Chocolate and White spotted. When Kennel Club Registries were organized and standards were imposed many of these color variations were not selected for breeding and were not permitted to be accurately registered- so we believe that any color variation seen in founding Mastiffs may still be expressed in a modern mastiff. We welcome the photos and pedigrees of Mastiff's with other non-standard color variations and would be happy to include them here in our Mastiff Color Expressions post.