Why are people of deccan are so different ?

Question

Peoples in countries of Deccan (countries like India, Afghanistan, Pakistan, Sri Lanka, etc.) have same hair color(black) but different skin color(light brown or brown or dark brown). But in the western developed countries, people have same type of skin color (white or black) but different hair colors (yellow, black ,white, etc.)
WHY IS IT SO ?

Answer 1

interracial breeding over time