Why do people have different skin color?

WHY PEOPLE TEND TO HAVE DIFFERENT BODY COLOR 

Now if asked why someone living in Africa is more darker than you , then mostly people reply that it is due to their surrounding and genetics. True that but there is more to it.

We have seen people skin color ranging from Dark brown to pale yellow but what causes them?..

Actually there are many factors that effect the skin color, but the most important determining factor is a substance called melanin which is a biological pigment. Melanin is produced within the skin in cells called melanocytes.

Greater the amount of melanin present in body darker the color of skin. Exposure to excessive Ultraviolet radiations from the sun is harmful for our body so the main purpose of melanin is to protect us from these rays. People of those areas where the the exposure of UVR is more frequent tend to have darker color .This is due to the fact that these people through time have developed abundant amount of these colored pigments that fight off the UV rays.

One research said that human populations over the past 50,000 years have changed from dark-skinned to light-skinned and vice versa as they migrated to different UV zones

FACT:

 Tanning works in the same way, by giving prolong exposure to sun we increase the production of melanin resulting in a darker skin color.

FACT 2:

 People also have different Hair textures due to this. In this case two type of melanin play an important role, eumelanin and pheomelanin. Generally, if more eumelanin is present, the color of the hair is more darker, and vice versa.