Where do people brown people originate from?

I know that many Europeans are either Anglo Saxon, Slavic, or from the Middle East or mixed with two or three, (like the french, italians, spanish, german, romanians, etc). Blacks come from Africa, Natives and East Asians come from Mongolia, but where people from India, Pakistan, Sri lanka, that whole region? I know there are races that look the way they do because of where they lives and the climate...but that region is very hot. Why do they not look black? Are they mixed with black and middle eastern? Please do not say this is a racist question. I am just reading a book on geneology and for some reason, that question came into my head.