The Border Collie comes in far more than black and white. This is a plain‑English, swatch‑by‑swatch guide to the coat colours and patterns of the breed — and the genetics that create each one.
This site offers genetic information for anyone wanting to understand Border Collie coat colours and patterns — whether you are a breeder planning a litter or simply curious about why your dog looks the way it does. Please enjoy your visit.
Fourteen building blocks make up every coat in the breed. Each card opens a plain‑English guide to the gene behind it — with the genotypes that produce it.
How coat colour genetics works — the two pigments, the loci and dominance.
Explore →The dominant, default coat: jet black and white, the breed's most common look.
Explore →A recessive B‑locus colour that turns black pigment to rich chocolate.
Explore →The dilution gene softens black to slate‑blue, and brown to lilac.
Explore →The masking gene: any genetic colour, hidden under gold to biscuit red.
Explore →Golden coats with black‑tipped hairs, from clear to shaded sable.
Explore →Tan pips over the eyes, muzzle and legs — the classic tri‑colour marking.
Explore →Stripes of dark pigment over a red base, governed by the K locus.
Explore →Patchy dilution that mottles the coat — and never skips a generation.
Explore →How the S series paints white collars, blazes and colour‑headed whites.
Explore →Flecks and roaning that fill the white areas as a pup grows up.
Explore →Blazes, full white faces and split faces — the endless variety of the muzzle.
Explore →Smooth, rough and everything between — length and texture explained.
Explore →How the B and D loci set nose leather, eye rims and iris colour.
Explore →Every coat is built from just two pigments — black‑based eumelanin and red‑based phaeomelanin. Genes only modify these two.
B, D, E, A, K, M, S and T — a handful of genetic locations decide colour, dilution, masking, patterns and white.
When a coat is masked or diluted, the nose, eye rims and lips reveal the dog’s true genetic colour.
Stack these genes and you get everything from a classic black tri to a lilac merle with china eyes.
