A moment please, and you are welcome to ignore me if you wish. But being a Christian, I believe the Bible before I believe any man.
Clearly, the first man and woman were Adam and Eve..and read again through Genesis, God does not assign them any melanin content..so obviously, they conceivably could be anywhere on the chart below.
Once dispatched from Babel, the people scattered..it would seem IMO that most differences are the result of adaptations to their given environment. The truly noticeable differences we see, are primarily cultural.
So far as the Hamitic curse...it is not God's curse. It was a curse pronounced by Noah upon his grandson Canaan,
The son of Ham. And that curse mentioned nothing about skin color, but rather that Canaan and his descendants would be servants to Shem and Japheth and their descendants. (Genesis 9:20-29)
Some confusion may have been provoked because the name Ham in Hebrew, indicates dark or black. That does
not necessarily mean that Ham was a black person, since it may have been a comparative judgement by
Noah & wife.
There historically are some Irish people who were referred to as "black Irish", but they were not at all black. They
were descendants of those sailors from the wrecked Spanish Armada of 1588, who floated to the shores of Ireland and took up residence there. They were "black" by comparison to the very fair Irish.
Now for the diaspora..people spread far and wide as God intended when he confused their language..
However, there is an error which raises it's head from time to time, which is called the "replacement theory", the "British Israeli" theory, and several other titles.
Their claim is that the so-called, "lost tribes" of Israel, ended up after their Assyrian and Babylonian captivity, migrating to western Europe, and then to America. This is a central part of the Mormons and Herbert W Armstrong's old, World Wide church of God..group, but not part of Biblical Christianity.
America has no real place in scripture, although there are a couple isolated statements which can be stretched to apply..
If somebody wants to refute me..please use scripture.. Other than that, just take it or trash it ! Just my $ .02 !