My pup's dam is a bicolor, she's listed as "black and tan" on the SV registry. I haven't turned in the papers for AKC papers yet, didn't know "bicolor" was an option on AKC. In Germany a bicolor is considered black/tan. Doesn't mean the pup will be a bi-color, the dam of your pup looks bicolor to me, although she doesn't have the toe penciling and leg penciling.
The top left is the father (sable) the right is the mother, bottom right is an uncle. My boy is bicolor because he has all the characteristics, but also his pedigree has bicolors and blacks. You should post a pic of your pup! Love puppy pictures, even better if he's a bicolor (I'm a little partial of course. :-))
I think you can tell pretty early if it's bicolor, if the pup has tar heels and toe and leg penciling. Hope the pics and explanation help. :-)
"An excess of size is an unserviceable feature for breeding, his powers of endurance, his speed and the smartness of his movements suffer in all circumstances. Giants are never nimble."-Creator of GSD