why do people have different shades of colours in their skin ?

Question: why do people have different shades of colours in their skin ?
- Keywords:
  colours,
  people,
  skin
Asked by mizzyfattz to Chris on 8 Mar 2014.
- Chris Cole answered on 8 Mar 2014:
  
  Although I work with medics who specialise in skin, I don’t necessarily know so much about skin itself. However, as I understand it skin colour comes from the amount of melanin in your skin. The more there is the darker the skin is.

Question: why do people have different shades of colours in their skin ?