question about a black puppy - Page 4

German Shepherds have two coat layers.  The (usually) coarse outer coat: for blacks this is black, and for sables this is a combination of colors on each hair (you will see it go from black to brown to black on one strand).  The undercoat: for blacks it is black but can be sun-bleached or lighten when it's about to fall out, and for sables it's some shade from white to a rich red or dark brown depending on the dog and the location on its body. 

Can both of you look to see if these lighter hairs are solid in color (suggesting undercoat).  Also if they are coarse like the outer coat or more soft like undercoat.  What I think you are experiencing, although I am just guessing here, is a solid black dog with a light undercoat where sables also have a lighter undercoat... a crossing over of genes. 

oso,
can you post a picture of the puppy you're talking about?

my pup's light hair is a silver, but all her siblings have very rich red color.  this isn't her undercoat, the silver hairs are one color, not banded like a sable, coarse like the outer coat.
 this is grandmother ot my girl: http://www.pedigreedatabase.com/gsd/pedigree/613892.html
a solid black, but still the lighter color on the britches and shoulder.  this is the extent of my girls coloring, her older sister has alot more silver down the side of her neck.

Years ago I had a bitch who LOOKED like a Bi color...  thumbprint over her eye, on cheek and feet up as far as the pastern... but if you back brushed her coat her entire undercoat was very light, and the lower 1/4 of each guard hair was light.  I called it a black sable... but she looked more like the pictures on this thread than what is generally refered to as a black sable.  Wish I had a picture of her to post, but lost them in a housefire a few years back.

Genetics is fascinating.  I wish I had the answer for you.  It is an adorable look and no doubt a conversation starter. 

Here is the puppy now at nearly  4 months - the markings have got more obvious if anything...

I had a dog out of a female colored/marked like this. Supposed to be a black dog. She belonged to a friend of mine. Bred to a blk/tan showline she produced black and tans and blanket b/t, very deeply pigmented. My dog was a blanket black/red only having red on her lower legs, no belly or face markings.

 Uber/Oso whatever the color, they are stunning to look at.