Grey (G)

Grey causes a horse to slowly turn to a grey coat over its lifetime. Grey horses occur when any horse has at least one grey gene (G). Horses will turn grey if they have:


  • Any base color + Gg
  • Any base color + GG

Fleabitten Grey

Fleabitten grey is the rarest form of grey and occurs in 5% of horses with Gg and 10% of horses with GG.

Types of Grey

Grey comes in several forms, with some greys determined by base color. These are:

  • Rose Grey – A horse with a bay or chestnut base coat with GG or Gg.
  • Steel Grey – A horse with a black base coat with GG or Gg.
  • Fleabitten Grey – A horse with GG or Gg with any base coat.
  • Light Grey – GG horses of any base coat.



Horses that have a grey gene will be born with “goggles” as foals, which is more noticeable at age 1. This is the first indicator your horse will grey out.

At ages 2, 4, 8, and 10 horses will slowly progress through several greying stages. The only horses that will fully go grey are those that are 10 years old and have two grey genes (GG).