We are dealing with several separate gene pairs:

1. the dog is either sable or saddle. (A locus)

2. the dog has either grizzle back or black back.

3. the dog is either "normal" or pinkie (E locus)

4. the dog has either red or wheaten phaeomelanin

5. the dog has either normal black or blue eumelanin (D locus)

Every Norwich has all these gene pairs and every one of them has two alleles there and are either homozygous or heterozygous for all these traits. All combinations are possible, but in some cases you just can't see the effect of some of these. Like when you have a sable (red) dog, you don't know what it has in its "grizzle/blackback" locus, and when you have a pinkie/red yellow dog, you don't know if it is genetically red/sable or saddle. (Except if it is out from two blackback parents, you KNOW the pinkie pup is blackback too!)