I'm Black and my skin-tone is fairly normal, I'm not light and not dark just in the middle. If I were to move to a place like Sweden, my skin-tone would lighten up because the sun would not be on me as much as it would if I lived in a place like South Africa where my skin-tone would darken because the sun would always be on me. I know this because I used to live in Alaska and then I moved to Texas and I got the same results in the change in my skin-tone but for now since it still feels like Winter down here in Central Texas and I rarely go outside because I absolutely despise insects, my skin-tone is in the middle.
Now, of course, Adam and Eve's (and whoever else lived during those times) descendants did not stay in Africa (which is where the garden of Eden is located) and supposedly the first people who walked the Earth looked like they were from the Middle East so I'd say they were tan-ish brown caramel (dead center in the middle of white and Black). Some of them went up North (please, remember that back then the Earth only had one mass of land called Pangaea) The North was cold and didn't have that much sun light so after centuries of living there they probably looked like today's average European (of course there was some gene mutation involved in that, too)
Other people went down South where there was a significant amount of heat and sunlight and after a few centuries of living there they probably looked like today's average African and some Middle Easterners such as the Tamil people and this also involved some gene mutation. And finally, some people traveled a little more to the East (Middle Easterners) or migrated all the way to the edge of the Sea (East Asians) and that pretty much sums it up.
However, I've heard multiple theories on why East Asians have slanted eyes, one of the most common being that they would always squint to see the land that was emerging from the Sea (The Americas, which was actually moving there after Pangaea had already been split into many different lands) and their faces got stuck that way. lol, I know that is really messed up but that's what I heard.
And Native Americans were East Asians that immigrated over to the "land that came from the Sea" after it had moved close enough to them.
So, technically, we are all cousins even if we're 1, 000, 000th cousins we are still all cousins. Considering, I don't believe God put more then 10 people on Earth.