Horse with extreme fleabitten pattern. The patch on the shoulder is not a bloodmark, it is just water. King Sonitas, AQHA stallion Owned by Teresa Coufal Website .

Some grays will have flecks of their base color in their coat; these are called flea-bitten grays. The flecks reflect the horse's base color; a bay or chestnut will have red flecks, a black will have black flecks, etc. Flea-bitten grays also get more colored (fleabitten) as they age, getting more speckles. Fleabitten grays are recessive, as non-fleabitten grays have had a fleabitten foal. Fleabittens are rarer than regular grays. Sometimes the flea-bites will touch each other, creating a large splotch, and sometimes a striking colored patch. These are called bloodmarks.

Gray horses can be born any color, as the gray pattern will show up on a horse having any base color or genes. A gray foal could be born cremello, black and white tobiano, an appaloosa leopard, etc., but the gray will eventually 'take over' and turn the horse gray. For that reason, people who breed for Appaloosa or Pinto coloration should avoid grays.

Because gray is a dominant color, breeds can consist entirely of grays. An example is Lipizzan or Lipizzaner horses, a breed that is almost exclusively gray. A rare bay or black, the offspring of two heterozygous grays, is occaisionally born and is considered good luck.