Color Genetics Guide
Chicken Color and Trait Genetics
What each gene does, how copies work, and why testing beats hatching in the dark.
Color genetics is where breeders lose the most time. A bird can carry a gene without showing it, so two normal looking birds can throw a surprise, and a beautiful bird can turn out to carry nothing worth passing on. A DNA test reports the genotype, meaning how many copies of the gene that individual bird actually has.
🧬 Copies are the whole point
Every bird carries two copies of each gene, one from each parent. A test comes back as zero, one, or two copies, and that number is what decides your pairing.
| Result | What it means | What it means for breeding |
| 0 copies | The bird does not carry the gene | It cannot pass it on at all |
| 1 copy | A carrier | Passes it to roughly half its chicks. For recessive traits the bird will not show it itself |
| 2 copies | Homozygous | Passes it to every chick |
For a recessive trait like lavender or chocolate, this is the difference between a pairing that produces the color and one that produces nothing but more hidden carriers.
🎨 The tests we run
Fibromelanosis
The gene behind black skin, black bone, and dark internal tissue in Silkies, Ayam Cemani, Svarthona, and Kadaknath. It is a dominant duplication, and visual grading is unreliable because a bird with one copy can look very dark. If you are breeding for consistent Cemani depth or selling black skinned stock, the copy count is the thing buyers care about. Fibromelanosis test.
Lavender
A recessive dilution that turns black into an even soft gray. Because it is recessive, a bird needs two copies to show it, and a single copy hides completely in a normal looking black bird. This is the classic case where breeders pair two blacks for two seasons and wonder why no lavender appears. Lavender test.
Chocolate
A sex linked recessive dilution producing a warm brown. Because it sits on the Z chromosome, it inherits differently in males and females, which is exactly why people mix it up with mauve. If you are pairing dilutions, read chocolate versus mauve before you set eggs. Chocolate test.
Blue egg gene
Determines whether a hen lays blue or blue based eggs, and how many copies she will pass on. Covered in detail in our blue egg gene guide.
✉ Testing genetics and sex together
The sample is the same for both, so most breeders run sexing and gene tests on the same bird at once rather than plucking twice. A freshly plucked feather with the soft base attached is all we need for either.
Turnaround is 2 to 3 business days from the day your samples arrive at the lab. Results and certificates load into your Pullidex account. Bundles of 8, 25, 50, and 100 samples lower the per-bird cost when you are grading a whole breeding pen.
🤔 When it pays for itself
Testing your breeding pen once tells you what every pairing in it can and cannot produce. The alternative is hatching a season, growing the chicks out, and reading the answer off the birds five months later, which costs a year if you guess wrong.