[QUOTE=frontierrots;722941]A breed is the sum of it's ancestors. To find what colors MIGHT be POSSIBLE in the breed look at the history and old standards
In this day and age, with the right/wrong gene combination you CAN get
normal black and rust, black & tan, black & brown or black & mahogany as you would expect
normal looking/marked Rottweiler but the markings are brindled
red & rust or blue & rust just like the undesireable colors in greater swiss
long coat
wire coat
BUT you will NOT get the ancient sable color unless mixed with something else
and blue merle is not even at all possible unless mixed with a blue merle breed somewhere in the recent past[/QUOTE]
Very true.
Add to that white markings on the chest (throw back from the greater swiss as well). All incorrect for the Rottweiler and current standars, but possible throw backs in the wonderful world of gene matching.
As Diane said - no merle appears anywhere in the breed history. Therefore, mix is the logical conclusion.