S = black
SrGrau = black recessive grey
Grau = grey
SrSW = black recessive Black&white
SrSWrGrau = black recessive black&white recessive grey
SrB = black recessive brown
others:
B = brown
SmB = Black but with Brown in the same litter
SW = black & white
SmSW = Black but with a Black & white in the same litter
etc.
So the basic colours are S (Black), B (Brown), SW (Black&white), Grau (Grey).
The first letter is always what colour that dog is. If there is a rB, rSW, rGrau it means that the dog is recessive in that colour (r = recessive). If there is mB, mSW, mGrau it means that the dog was from a litter with that coloured puppies (m = "with" )