Question: Why do people have different coloured eyes?

Ceri Dare answered on 19 Nov 2014:

The iris in your eye (the coloured circle) is a muscle which controls how much light gets into your eye. It starts off blue in everyone – and if you look into the eyes of newborn kittens or puppies, they are almost always blue.

Then the different colours depend on how much melanin you have – melanin is the same pigment which gives people darker skin, the more melanin the darker your skin, eyes and hair look. So people of African descent often have dark brown eyes along with dark skin and brown hair, whereas I have pale skin which burns easily, blonde hair, and blue-green eyes.