Just musing really but if a silver sable GSD was mated to a black & tan/gold what colour(s) could you expect or isn't it that cut and dried?

Looking at the site below sable is dominant over the black tan (bi-colour it seems to be called in the breed) so you would have at least a 50% chance of more sable.
If the sable parent has two sable genes all pups will be sable, if it carries the black tan gene then 50/50 chance of sable or black tan, if it carries the saddle gene then then 50/50 chance for sable or black tan saddle. If both parent carry ressive black gene there is a 50% chance of sable, 25% chance of black tan and 25% chance of black.

But those chances are for each pup to be born that colour so each pup has 50% chance not a half of the litter will be. so depending on luck you could still get all pups end up the same colour. So the last example involving ressive black if lucky or unlucky all the litter could be black.

The rest then depends on if the parents carry any of the dilution genes (liver, blue, white ect), as well as intensity and white spotting genes

http://www.jmadesign.com/Frankenhaus/colorgen01.shtml

Silver sables appear to be very pale, so some kind of lightening gene is going on - probably the I for Intensity gene, which tends to be recessive.

It's present in quite a few breeds (used to be called "chinchilla" and thought to be on the C locus, but that's been disproved by molecular analysis, so is now properly called Intensity). Intensity

Jo Stockbridge is right about the "sable" colouring - genetically it's termed Wolf Grey or Wolf Sable a(w) and is dominant to black-and-tan a(t).
Wolf Sable
Black and Tan

Interesting, thanks for the replies. I didn't know sable was dominant to the Black and Tans as they're not seen very often and I don't recall seeing any in the ring with the colouring of my bitches dam. Maybe it's more of a working line 'thing'.