Mendel-exact, not vibes
Every cross is real per-locus inheritance math. Where a color involves modifier genes or messy expression, we say so instead of faking a clean percentage.
Open reference · free foreverGuides / Color Genetics
The open-source directory for breed genetics.
No horoscopes, no vague advice. Clean, Mendel-exact inheritance guides, trait breakdowns, and live color calculators built for the color-obsessed communities in the breeding world, starting with French Bulldogs and expanding one locus-accurate breed at a time.
2 live
Interactive calculators, more shipping monthly
9 loci
Modelled per breed, exact Mendelian crosses
$0
Un-gatekept, no signup, nothing stored
Live now · interactive
Fr
Canis familiarisLive guide
French Bulldog
The full nine-locus coat map, fluffy, blue, lilac, merle and pied, with a live litter predictor.
Open the guide →Pillar + calculator
Ab
Canis familiarisLive guide
American Bully
Tri, ghost tri, lilac, champagne and merle across the nine loci, with ABKC and UKC status and a live litter predictor.
Open the guide →Pillar + calculator
Dogs 9
DbDoberman PinscherBlack, red, blue and fawn with the color-dilution alopecia risk.
PdPoodleFading, phantom, parti and abstract patterns that shift for years.
LbLabrador RetrieverBlack, chocolate and yellow off just two interacting loci.
DxDachshundDapple, brindle, piebald and the double-dapple health line.
GsGerman ShepherdSable, black-and-tan, panda and the recessive black cross.
AsAustralian ShepherdMerle-heavy program genetics and the double-merle line to avoid.
ChChihuahuaOne of the widest color spreads in dogs across every locus.
GdGreat DaneHarlequin, merle, mantle and the lethal white pairing.
CkCocker SpanielRoan, ticking and parti patterns on the spaniel base.
Cats 3
McMaine CoonTabby, tortie, dilution and the sex-linked orange locus.
BnBengalRosetting, charcoal, snow and the glitter modifier.
SxSphynxFull color genetics expressed on a hairless coat.
Horses 2
QhAmerican Quarter HorseBay, chestnut, dun, roan and the overo lethal white line.
ArArabianGrey progression, bay and chestnut on the classic base.
Reptiles 5
CgCrested GeckoWhere Mendel gets messy, line-bred traits and structural morphs.
BpBall PythonCo-dominant and recessive genes stacking into designer combos.
LgLeopard GeckoAlbino lines, patternless, and the Enigma neurological caveat.
CsCorn SnakeThe recessive-morph classroom, amel, anery, and their combos.
BdBearded DragonHet translucent, hypo, zero and the silkback welfare note.
Why software matters
Understanding the loci is half the battle.
Mendelian math is easy. Data persistence is hard. Reading these free guides will help you plan your next pairing, but tracking those traits across five generations without a spreadsheet breaking is where serious programs struggle. Read the library for free, then use Breed Ledger to automate the infrastructure.
01Read the breed guide and learn the loci.
02Predict a pairing with the live calculator.
03Record every genotype in Breed Ledger, for good.
The house rules
How every guide
in here is built.
Written for operators
These are reference desks for people running real programs, genotype notation alongside plain color names, health flags called out, registry status kept separate from worth.
Free and un-gatekept
No signup wall, no drip funnel to read a guide. The tools run entirely in your browser and store nothing. The business is the software, not your email address.