I have meant to try this thread for a long time, but something always seems to happen to prevent that. Maybe that was a good thing, I dont know, but I finally have a few moments so I thought I would go ahead and give it a shot.
First, there are two concepts to get nailed down first.
1. Classification of objects is for the purposes of function, mostly, and tends to sort things based on function and behavior. If we categorize vehicles we tend to sort them by categories like 'truck', 'sedan', 'van', coups, etc, as these are reflective of the function, purpose and the intended behavior of the vehicle buyer. The color of the vehicles paint job would be a latter consideration normally.
2. Gray scale is a continuum of gradual change, with few if any white pixels and nearly all black at one end to the other end with almost entirely white pixels. As o ne transitions from one end to the other there seems to be a clear gradual change of the scales darkness, but if you bent the page and placed the two ends side by side you see a contrast that might suggest a basic essential difference that is not really there.
That out of the way, we have to look at the simple fact that racial 'science' has never been much more than a pseudo science. While one can use scientific methods to ID a skeleton by racial criteria, the criteria itself is arbitrary and based on little more than geographical location.
There is also no clear delineation between races, how many races there are or what ethnic groups belong to which. Most people recognize the three basic races, Caucasoid, Negroid and Mongoloid, but few realize that there are other categorizations as well, such as the Polynesians who some consider Caucasian and others consider Mongoloid and yet others consider an entirely separate race. Some say that there are seven races, in addition to the previous three we would also have Amerindians, Australoids, Polynesians, and Dravidians.
Now the term 'white' was in the old days used to mean northern Caucasians, and yet few would say today that the Greeks and Italians are not white. Certainly the US Census bureau does not consider Italians to be nonwhite. And yet many consider Latin Americans to be a strange new race called 'Hispanic' though they are almost entirely Caucasian and Mestizo and the later has been long considered a subgroup of Caucasian.
The racialist 'Identity Politics' ideology uses racial categories to define its constituent groups and they like to split anyone away from the majority population by any means available, so if you are white Hispanic, then you are not white, just Hispanic. If you are half white half black like Obama, then you are black. To them you are anything you prefer to be, even a different species, if that is what your heart tells you that you are.
But there is nothing that essentially defines humanity along racial lines. It is just ethnicity grouped together into arbitrary categories, like whether Dravidians are Caucasian, Polynesian or their own separate race.
It seems to me that it is ethnicity and culture that most defines who we are by how we behave according to the things we have been taught to believe from childhood. Not what is in your DNA.