The amount of pigment known as melanin in your iris determine your eye color. The more melanin you have the darker your eyes are. The less you have the lighter your eye color. A large number of babies are both with blue eyes, and within the first six to 36 months eyes and melanin develop and the eye color can change. While melanin is the main pigment, lipochrome is a contributing factor to green eyes, as well as gold tones that might appear. 

The amount of melanin in your iris is determined by genetics. The two major genes that contribute to eye color are OCA2 and HERC2. Specifically, these two genes contribute to the development of brown and blue eyes, while multiple genes participate in a minor way to produce other eye colors like green or hazel. As a group, those genes also contribute to hair and skin color. 

Brown eyes: 

  • Most common eye color
  • Result of having a large amount of melanin 

Hazel eyes:

  • Appear to switch from brown to green or a combination of the two
  • Often have a brown ring at the outer edge

Green eyes:

  • Least common eye color
  • Linked to northern and central European decent
  • Rare in men

Blue eyes:

  • Linked to European decent
  • Eye color of most newborn babies