01 / The basics
Every color is two pigments, switched and diluted.
An American Bully only makes two raw pigments: eumelanin (black-based) and phaeomelanin (red/tan-based). Every color you have seen advertised is those two pigments being switched on or off, diluted, restricted to patches, or diluted again. There is no "blue gene" that paints a dog blue. Blue is black pigment turned down.
Each switch lives at a specific locus (a location on a chromosome), and a dog carries two copies of each, one from each parent. Write them as a pair like D/d. Capital letters are usually dominant (only one copy needed to show); lowercase are recessive (two copies needed). Get those pairs for both parents and the litter is just arithmetic.
- Dominant traits (merle, dominant black) show with a single copy.
- Recessive traits (blue, chocolate, tan points, champagne) need two copies to appear.
- A dog can carry a recessive invisibly and pass it on, the reason DNA panels exist.
02 / The map
The nine loci that decide a bully's coat.
These are the switches the predictor models. Most bullies are clear (homozygous common) on most of them, so you only need to know the ones a parent actually carries.
| Gene | Controls | The color allele |
|---|---|---|
| MLPH | Dilution, blue Turns black to blue, chocolate to lilac | d/d |
| TYRP1 | Brown, chocolate Turns black pigment to brown | b/b |
| ASIP | Agouti, tri / fawn Tan points (tri) or fawn / sable | at/at · Ay |
| CBD103 | K locus, brindle / solid Solid (KB) hides agouti; ky lets tri show | KB · kbr · ky |
| PMEL | Merle Patchy dilution, dominant, a DQ | M/m |
| MC1R (E) | Extension Cream / champagne (e/e) or mask (Em) | e/e · Em |
| MITF (S) | Spotting, pied White piebald spotting | sp/sp |
| FGF5 | Coat length, fluffy Long coat, rare recessive | l/l |
| MFSD12 | Intensity Washes red/tan toward cream | i/i |
03 / Base colors
Black, blue, chocolate, lilac & champagne.
Every bully starts from one of a few base colors, set by the dilution (blue) and brown (chocolate) genes, plus recessive red on a dilute base for champagne. Patterns like tri and brindle sit on top of these.
Full-strength eumelanin. The default base every other color is built from.
ABKC + UKCBlack pigment diluted to a soft blue-grey. The gateway exotic color.
PopularBlack pigment turned brown by the recessive brown gene.
PopularBlue and chocolate together, a pale silvery taupe. One of the rarest bases.
PopularRecessive red on a dilute base: a pale, warm champagne coat.
Popular04 / Patterns
Tri, ghost tri, brindle & merle.
Patterns overlay a base color. Tri (tan points) is the defining bully pattern and stacks on any base, which is why lilac tri and blue tri sit at the top of the market. Ghost tri is the same tan-point genotype masked by dominant black. Merle is the one pattern the two registries treat differently: ABKC permits it, UKC disqualifies it.
Tan points on the face, chest, and legs over a black base (tri-color).
PopularTan points over a blue base. Tri stacks on any base color.
PopularTan points over a lilac base, top of the color market.
PopularGenetically tri but masked by dominant black, so points read as faint ghost markings.
PopularDark tiger-striping over a fawn base. A traditional, fully accepted pattern.
ABKC + UKCA patchy, marbled dilution. Permissible under ABKC; a UKC disqualification.
UKC DQGo deeper on each: tri color, lilac tri, champagne, ghost tri, and merle American Bullies.
05 / The in-demand colors
What the market actually chases.
The colors that command the highest prices are the stacked ones: lilac tri (blue + chocolate + tan points), champagne, and merle. Each needs several uncommon genes to line up at once, which is what makes them rare, not any single "rare gene." Unlike the AKC world, none of these are registration problems for a bully; the bully registries accept them all except merle.
06 / Health
The one pairing genetics tells you to avoid.
Color is mostly cosmetic, with one real exception. Breeding merle to merle gives roughly a quarter of the litter two merle copies (M/M, double merle), strongly linked to deafness and serious eye defects. This is a genetics decision, not an aesthetic one, and it is why the predictor raises a dedicated warning the moment both parents are set to merle. Double merle is the color-linked risk; inbreeding is the other one. Run any pairing through the free COI calculator before you commit to see how concentrated its bloodline is.
Never breed merle × merle. To produce merle safely, pair one merle (M/m) with a non-merle (m/m). Every puppy then has a healthy single dose or none, and zero risk of a double merle.
The other one to know: color dilution alopecia can affect some dilute (d/d) dogs, thinning coat over the diluted areas. It is manageable and not universal, but worth disclosing on blue and lilac lines.
07 / Registry status
ABKC and UKC both accept the fad colors.
This is the big difference from the Frenchie world. The American Bully's registries, the ABKC and UKC, accept the exotic colors. Blue, chocolate, lilac, champagne, and every tri variant are all fully acceptable in the show ring under both.
Where they differ is merle. The ABKC standard states that all colors and patterns are permissible, so merle is acceptable under ABKC. UKC accepts every color except merle, which it disqualifies. So a merle bully is ABKC-showable but a UKC disqualification (albinism is a disqualification in both). The calculator lets you toggle ABKC or UKC to see a color's status one registry at a time.
Free tool · no signup
Stop guessing carrier odds on scratch paper.
Plug your parents' DNA panel results straight into the live engine to map your litter's exact colors, hidden-carrier percentages, ABKC and UKC status, and health alerts.
08 / FAQ
Common questions.
The ABKC standard states that all colors and patterns are permissible, so nothing is a color disqualification there, merle included. UKC accepts every color except merle, which it disqualifies (albinism is a disqualification in both). So the fad colors, tri, champagne, blue, chocolate, and lilac, are accepted by both, and the two registries differ on exactly one pattern: merle is fine for ABKC and out for UKC.
A tri shows clear tan points on the face, chest, and legs, genetically at/at with the K locus allowing it (ky/ky). A ghost tri is also at/at but carries dominant black (KB), which masks the points so they read as faint ghost markings. A ghost tri still carries and passes on full tri.
Lilac tri sits near the top, because it needs blue (d/d), chocolate (b/b), and tan points (at/at) all lined up at once. Champagne and lilac are rare bases in their own right. Rarity comes from how many recessive genes have to stack, not from any single gene.
Yes. Under the ABKC standard all colors and patterns are permissible, so merle is acceptable and showable in ABKC. UKC accepts every color except merle, so a merle is a UKC show disqualification, though a merle from registered parents can typically still be registered. The bigger issue is health: breeding merle to merle risks double merle, linked to deafness and eye defects, so responsible programs pair a single merle only with a non-merle.