A bi-color pup and Black and Tan or Red pup almost look identical when they're young. If you're sure the dad is bi-color there is a chance the puppy is too, but its hard to tell you for sure. I had a bi-color that came from a Bl and Rd female and a saddle male. The breeder should be able to tell you what the pup will be. A good breeder knows what they're breeding for even with color.
Uma - Red & Black Female GSD
Lili - Red & Black Long Stock Female GSD
Molly - Tan & Black Female Yorkie Mix