A Guide for Breeders, Stud Owners, and Labrador Enthusiasts
In the world of Labrador Retrievers, “Black, Yellow, and Chocolate” isn’t just a description—it’s a complex genetic puzzle. Whether you are searching for a stud to complement your bitch or trying to predict the rainbow in your next litter, understanding color genotypes is your most important tool.
At The Labrador Directory, we make it easy to Search Studs by Genotype, but first, let’s break down what those letters actually mean.
The Two Primary Genes: “E” and “B”
Labrador color is determined by two main loci (locations on the chromosome): the E Locus and the B Locus. Every dog inherits one letter from its sire and one from its dam for each locus.
1. The E Locus (The “Mask” or “Switch”)
The E gene determines if a dog can actually show its dark pigment (Black or Chocolate).
- Big ‘E’ (Dominant): Allows the dog to be Black or Chocolate.
- Little ‘e’ (Recessive): The “Yellow switch.” If a dog has two little ‘ee’, it will be Yellow, regardless of what the B locus says.
2. The B Locus (The “Intensity”)
The B gene determines how dark that pigment is.
- Big ‘B’ (Dominant): Results in Black pigment.
- Little ‘b’ (Recessive): Results in Chocolate pigment.
Decoding the Common Genotypes
When you see a code like EeBb, here is how to read it:
| Genotype | What it looks like (Phenotype) | What it “Carries” |
| EEBB | Black | Pure Black (No Yellow or Chocolate) |
| EeBB | Black | Carries Yellow |
| EEBb | Black | Carries Chocolate |
| EeBb | Black | “The Trio” – Carries Yellow & Chocolate |
| eeBB | Yellow | Yellow (Black pigment/nose) |
| eeBb | Yellow | Yellow (Carries Chocolate) |
| eebb | Yellow | “Dudley” (Chocolate pigment/liver nose) |
| EEbb | Chocolate | Pure Chocolate (No Yellow) |
| Eebb | Chocolate | Chocolate (Carries Yellow) |
Use Our Color Calculator
Want to know what genotypes paired together will result in?
Use our inheritance calculator to input the sire and dam’s color and see what the offspring will be.
We even included the Punnett square so you can see the full data!
Why This Matters for Your Breeding Program
Understanding these codes isn’t just about “pretty colors.” It’s about predictability and health.
Avoiding the “Dudley”
While “Dudley” (Yellow dogs with pinkish/chocolate noses and eye rims) are wonderful pets, they are a disqualification in the AKC show ring. By testing your dogs and using our directory to find eeBB studs for your yellow-factored females, you can ensure correct black pigment in your puppies.
Preservation Breeding
An EEbb chocolate Labrador bred to an EEBB black Labrador produces 100% EEBb black puppies. Every puppy carries the recessive brown allele (b), and none carries the recessive yellow allele (e).
Sources: UC Davis VGL: MC1R / E locus | UC Davis VGL: Brown / B locus
Take the Next Step
Ready to put this science into practice? Use our specialized filters to find your next match:
- View Studs: Black Carrying Chocolate and Yellow (EeBb)
- View Studs: Pure Chocolate (EEbb)
- Try the Labrador Color Calculator
Health Note: While color is fun, health is paramount. Always cross-reference color genotypes with vital health clearances like OFA Hips/Elbows, EIC, and HNPK. You can filter for these clearances directly in our Advanced Search.
Author: Michael Kovach
Leave a Reply