A bi-color German shepherd is black with tan legs. The toes have very thin black stripes called pencil markings. Most German shepherds are a mixture of black and tan, but bi-colors have a distinct pattern from these two-color dogs that requires the majority of the coat to be solid black.
The standard two-color pattern on a German shepherd is called saddle back. Saddle back dogs have a large black spot in the middle of the back and a tan or red coloration elsewhere. Dogs with a larger black spot that extends down the sides are called blanket back. Dogs that have bands of color alternating on each individual hair are called sable. Bi-color German shepherds are sometimes called tarheels because of the distinctive black coloring that appears on each leg's heel.