Skin color really is just an evolutionary adaptation to the amount of heat and sun that a certain people are exposed to. For example, the first Causcasion people were basically what you would call a "white person" when they first evolved in Asia Minor. However, when they migrated in all directions across to Europe and Asia, they adapted to their surroundings, in some instances a huge change in skin color occured. A huge change like this would be for example Indians. When Caucasions arrived in India, the climate was SUBSTANTIALLY more humid and very few other places has as much sun exposure in the world. However, the people adapted over time, and through this adaptation, we now have the very dark skinned Indian people. (Note yes, Indian people ARE Caucasion). While Asians from North Asia tend to have significantly fair skin, South East Asians tend to have much darker skin, do to the larger amount of heat and sun exposure. Thats why you can be fairly light skinned, and then after living in a place like Arabia, eventually your family genes will change and the generations will become much darker skinned, or you can just get a tan! Haha, but thats basically Skin Color in a nutshell. P.S. BTW im an Irish(white), Greek(Mediterannean), Malaysian(Asian) mixture and during the summer i can be as white as can be, and during the summer i can develope very dark skin, it all depends on your ethnicity and what climates you are exposed to.