Basic Color Genetics: Black and Chestnut Agouti

The black and the chestnut agouti are in the same "black" family.   The black is "non-agouti" pattern and the chestnut agouti is the "agouti" pattern.   

The most basic color in the wild rabbits is the chestnut agouti: A-B-C-D-E-
The upper case letters show that these are the dominant genes, the - indicates that there may be another dominant gene or a recessive gene at that location but it's not obvious from the rabbit's appearance.   The photo above is a chestnut agouti English Angora.   "A" shows it's an agouti pattern,  characterized by the banded undercoat and chestnut tipping, white or tan circle around the eyes and under the nose, the tummy is light tan or whitish.  "B" indicates that it's black based.  "C" indicates it's full colored.  "D" indicates it's a dominate color thus the rabbit should have brown eyes. "E" indicates that the color is extended to all over the body.   

This is the same rabbit under the sun.   The color looks lighter but it's due to the light reflection.

The chestnut agouti babies are born solid black on the back and head without the tips.  The inside of the ears are pink and the tummy is also pink.   The tips will develop when the hair/wool starts to grow, the pink turns into tan or white.

This is black rabbit.  The difference between a black and a chestnut agouti is only by the pattern:
aaB-C-D-E-
If you compare the color genes of the chestnut agouti and the black, the difference is in the location of A.   The black is non-agouti, which indicates that there is no white or tan circle around the eyes or under the nose, no tipping.    The black color is all over the body.    aa is recessive.    Two black parents cannot produce a chestnut agouti offspring but two chestnut agouti parents may produce a black offspring if both carry the recessive "a" gene.

This is also a black rabbit but due to the sun the color is lighter.

The black babies are born solid black from the back to the tummy.  No pink anywhere.   The face will keep the black color but the rest of the body will turn gray when the wool grows.