Nose and Eye Coloration
The "B" series gene has some effect on the color of the nose, eye rims, lips, as well
as the iris (color) of the eye.  The "B" series only effects the eumelanin pigment.  
The eye color for the black dog ranges from yellowish to dark brown.  




"B/B" or "B/b" allows the production of black pigment,



whereas "b/b" produces brown pigment wherever the dog would otherwise have
produced black.  The eye color of the brown dog ranges from greenish to amber to
orange to brown.




A dog that is brown (chocolate) will have the genotype of "b/b D/D" or "b/b D/d" and
will have a brown (chocolate) nose (because the "B" gene is not present and the
"D" gene is in the dominant form).  



If the "D" gene is in the recessive form ("d"), along with "b/b", then the nose would
be a rosey-gray color --- like that of a fawn colored dog.




The "D", or dilution series gene, also has some effect on the color of the nose, eye
rims, lips, as well as the iris of the eye.  Eye color can range from very pale to light
brown.




"D" is dominant and allows full pigmentation, whereas "d" is recessive and dilutes
the pigment.  The "D" series, in the homozygous recessive form ("d") effects both
eumelanin and phaeomelanin, (in theory) by causing the clumping of the pigment
granules in the hair.   
A dog that is dilute - black (called blue in the Kelpie breed) will have the genotype
of "B/B d/d" or "B/b d/d" and will have a gray nose (because the "B" gene, which
would normally cause the nose to be black, is now diluted to gray).
To view the pictures
in a larger format,
click on the picture.  
If the cream colored dog is brown (which is masked by the cream color) the nose
color will be brown.




If the cream colored dog is black (which is masked by the cream color), the nose will
be black.


Depending on what is at the B and D Locus on the cream colored dog, the eyes
can range from very pale to brown.