COLOR GENETICS
in German Shepherd Dogs
This will only cover the "common" German Shepherd colors - Sable, Black and tan, Bicolor and Black.
Please note that white is not a "color" but a masking gene, which I will not cover here.
Color genetics is very fascinating to me.  Having read many articles on it, and studying it within the lines in my own kennel, I have
noticed that most articles make it sound much more complicated than I think it is.  So, I thought I would simplify it as much as possible.


The order of color dominance is:  Sable
(aw), Black and Tan (as), Bicolor (at), and Black(a).

Each dog inherits 2 color genes - one from each parent.  

One is the dominant (expressed) gene, and that is the color that the dog IS.  

The other recessive (hidden) gene is a secondary color that is carried and can be expressed in that dog's puppies.


Sable is never recessive.  If a dog inherits the sable gene, it will BE sable.  A pup cannot be sable unless at least one parent is sable.

Black is completely recessive to all other genes, so both parents must give a black gene for a puppy to be black, and the only color that
dog will pass on to its puppies is black.    

The table below explains things pretty well:
THE COLOR OF THE PARENT ONLY TELLS HALF THE STORY
IT IS IMPERATIVE TO KNOW THE RECESSIVE GENES EACH PARENT CARRIES TO ESTIMATE THE COLORS TO EXPECT IN A LITTER
***Always remember the puppies can inherit the recessive color gene from both parents, and not be colored like either one of them***
the more dominant (expressed) color is always listed first, and the recessive second


SABLES:
Homozygous sables (aw+aw), no matter what they are bred to, will only produce sables, because sable is the only gene the dog has to pass
on, and it is always dominant.

If a pup from a breeding between two sables inherits a black and tan gene from one parent, a pup would be still sable with black and tan
recessive (aw+as).  These are often "pattern sables".  Pattern sables sometimes are patterned very much like a black and tan, but the saddle
is not solid, and has a lighter undercoat (see color examples below).  

It is possible for two sables with black and tan recessive (aw+as) to both pass on the black and tan genes (as+as), in which case a pup would
be truly black and tan.  

It is possible for two sables with bicolor  recessive (aw+at) to both pass on the bicolor genes (at+at), in which case a pup would be truly
bicolor.  

It is possible for two sables with blk  recessive (aw+a) to both pass on the black genes (a+a), in which case a pup would be truly black.

If a sable with black and tan or bicolor recessive is bred to a sable with black recessive, it is possible to get black and tan or bicolor pups, but
not black pups, as both parents must pass on a black gene for the pup to be black.

BLACK AND TAN TO HOMOZYGOUS SABLE :
If you breed a homozygous black and tan  to a sable,  and the sable is homozygous, all pups will be sable (aw+as).
If the black and tan carries bicolor recessive, the resulting sable pup could carry the black and tan (aw+as) or bicolor recessive gene (aw+at)
If the black and tan carries blk recessive, the resulting sable pup could carry the black and tan (aw+as) or black recessive gene (aw+a)

BLACK AND TAN TO SABLE w/RECESSIVE:
If the black and tan is bred to a sable with recessive
color, resulting puppies can be sable, black and tan, or whatever recessive color the
parents carry.


B
LACK AND TAN TO BLACK AND TAN:
If two black and tans are bred together, resulting puppies can be black and tan, or whatever recessive color the parents carry

BLACK AND TAN TO BICOLOR:
Pups can be black and tan, bicolor, or black if both parents carry black.

BLACK AND TAN TO BLACK:
Can be black and tan, but if the black and tan carries black recessive, pups can be solid black.

BICOLOR TO BLACK:
Bicolors or blacks if both parents carry black.
COAT COLOR EXAMPLES
THERE ARE ACTUALLY MANY DIFFERENT SHADES AND PATTERNS ON SABLES.
You may hear people refer to "red Sables"  Cream Sables, Silver sables, etc.. but this is a "nickname" and not official.  With AKC and UKC, there is only
"Sable".  The SV in Germany categorizes them by darkness:  Grau (gray) is a plain sable; dunkel grau (dark grey) is dark sable, and tief dunkel grau
(deep dark sable) - which many refer to as black sable.  Germans further categorize them by the colors in their sable - grey-brown-yellow etc, and the
mask/markings.
average sable - grau
Jewel vom Alt-Ostland  (Yvett daughter)
sire was black (a+a), dam homozygous sable (aw+aw)
So, Jewel is aw+a
homozygous sable - grau
Y
vett vom Schaferliesel
homozygous sable (aw+aw)
darker sable - (dunkel grau)
Jo
rdan vom Alt-Ostland  
sire was black (a+a), dam p
attern sable (aw+aw)
So, Jo
rdan is aw+a
"black" sable - (tief dunkel grau)
Je
ster von Lord Fandor
sire was black (a+a), dam sable (aw+aw)
So, Je
ster is aw+a
BLACK AND TANS
CLASSIC "Saddleback" BLACK and TAN
Hero vom Steinbusch
both parents black and red
Hero is as + as
UNLESS OTHERWISE SPECIFIED, ALL DOGS LISTED WERE OWNED or LEASED BY ALT-OSTLAND, and ARE 100% EAST GERMAN DOGS
"PATTERN SABLE"
WILL vom ALT-OSTLAND
sire pattern sable aw + as
dam dark sable    aw + a
Will is aw+as
"PATTERN SABLE"
V
ENUS vom GRAFENTAL
sire pattern sable aw + as
dam p
attern sable    aw + as
V
enus is aw+as
BLACK AND TAN "BLANKET BACK"
Denwolf's JAZZ vom Alt-Ostland
sire: blk sable aw+a
dam pattern sable aw+as
Jazz is as+a
MELANISTIC or HEAVILY BLANKETED BLACK AND TAN
Q
uindt vom Alt-Ostland
sire: blk a+a
dam pattern sable aw+as
Q
uindt is as+a
BLACK AND TAN "BLANKET BACK"
I
van vom Oelmannsdorf
sire: blk  a+a
dam b
lack and tan as+a
I
van is as+a
BICOLORS
There is a bit of controversy as to what divides bicolor from black and tan.  The easiest answer is a DNA test.
Aside from doing the DNA test, most people say a bicolor should exhibit minimal markings on the body except on the lower legs, and have the black "tarheels"
BICOLORS like this girl (at+a) are particularly fascinating to me.  Her sire was black, which is not so complicated (a+a).  Her dam (at+a), however was a dark
bicolor from a pattern sable sire, and her dam was a sable with black recessive (aw + a).  I can understand the bicolor puppy coming form a bicolor and a black,
but her dam being bicolor is more of a mystery.  One can only assume she inherited the blk and tan recessive gene from her sire and the black recessive from
her dam.  It's interesting that she is so much darker than the black and tans in her pedigree, but it happens.
AND LAST BUT NOT LEAST:
THE BLACKS
Regardless of the color of the parents, all blacks are a+a because they inherited a black gene from each parent
Golf vom Clausberg a+a
Sire was black, dam was
sable with blk recessive