A - Bay, dominant to tanpoint and self. Restricts eumelanin to the points of the horse.
at - Tanpoint, recessive to Bay and dominant to self. Allows eumelanin on the majority of the horse but not the 'warm' parts such as flanks resulting in Seal Brown.
a - Self, recessive to bay and tanpoint. Allows eumelanin to be expressed over entire body.
C - Normal color, incomplete dominant to crème. This means it takes two copies of the C gene to have normal color.
ccr - Crème.
C/ccr will make bay into buckskin, black into smokey black and chestnut
ccr/ccr will make bay into perlino, black into smokey cream and chestnut
Cch - Champagne, dominant to non champagne.
Cch will make bay into amber champagne, black into classic champagne
and chestnut into gold champagne.
cch - Non champagne, recessive to champagne.
D - Dun, dominant to non dun. D will make bay into zebra dun, black and
smokey black into grulla, chestnut into red dun, buckskin into yellow dun,
palomino into linebacked palomino, and the crème colors into linebacked versions.
d - Non dun, recessive to dun.
E - Dark, dominant to recessive red.
e - Recessive red, recessive to dark.
F - Non flaxen, dominant to flaxen.
f - Flaxen, recessive to non flaxen. In its homozygous form (f/f) it will result in a bleaching effect on the mane and/or tail of chestnut horses. It has no effect on eumelanin.
G - Grey, dominant to non grey.
g - Non Grey, recessive to grey.
K - Dominant dark. Epistatic to the A locus this gene will make a horse black (depending on the dilution modifiers it carries) regardless of what genes are present at the A locus. i.e. A/at E/E K/- will be a black horse. K is masked by e/e.
kbr - Brindle. The inheritance of brindle in horses is not understood at this time so I followed the currently accepted theory in dogs for brindle genetics. It is recessive to K and dominant to k.
k - normal.
Pa - Pangare also known as mealy. This gene is dominant to non mealy (pa) but is only exhibted on bay, brown and chestnut based colors. It has no effect on black based colors.
pa - Non mealy, recessive to mealy.
R - Roan, dominant to non roan.
r - Non roan, recessive to roan.
Rb - Rabicano, dominant to non rabicano.
rb - Non rabicano, recessive to rabicano.
Z - Silver, dominant to non silver.
z - Non silver, recessive to silver.
A few helpful hints:
G - Grey masks all other colors.
A horse with one or two G alleles will be grey no matter what.
A G/G horse will only have grey foals.
e/e - Recessive red (commonly called chestnut) will mask bay, black, and silver.
An E/E horse will never have a chestnut/palomino/cremello foal.
Cch - All champagne variations mask silver.
To - Tobiano
to - Not spotted.
Ov - Frame Overo. Lethal in its homozygous (Ov/Ov) form
ov - Not spotted.
Lp - Appaloosa Spotted aka Leopard Complex
lp - Not appaloosa spotted
Sa - Sabino. In its homozygous form (Sa/Sa) it results in Maximum Sabino which can result in a nearly all white to all white horse.
sa = Not sabino
Spl - Splashed White.
spl - Not spotted.
I have included a generic unnamed genetic disorder in the game. This disorder is an autosomal recessive trait which means that it occurs equally in males and females and it takes two copies of the gene to be affected. Carriers will not have any "symptoms" so the only way to find them is to DNA test the horses. Affecteds will be affected in the show ring. Their scores will be cut in half making it impossible to show them to any legitimate wins. The point of adding this disorder to the game was twofold. One to help educate about genetic disease and how to "breed through them" to a clear line and two to add challenge to the game. When you DNA test your horses you will get one of three results (provided all is working as it should LOL): Clear, Carrier or Affected. It is each individual breeders choice how they go about clearing their lines of the disorder and there are several methods. One is to discard any carrier or affected but this can cost the breed some valuable genetics for the other inherited traits. One can also formulate a plan to breed through to clears using the carriers or even the affecteds. By utilizing clears to breed to them they are assured of never producing any affecteds and at worst more carriers. Eventually they will be able to produce a clear line that still retains the other desired inherited traits. I hope this gives you some insight into breeding and the choices that must be made as well as making the game more challenging and fun.
I could lay all the color combos out nice tables that would lead you straight to every combination, but where would the fun be in that? LOL What I've given you above is plenty to find the combinations to make the colors you want.