The PURE STUPIDITY of it all !!!
Nobody is white as snow, nor black as anthracite coal. Everybody is somewhere in between !
Grouping by color is simply another way of channeling hatred. During the Nazi era, Jews were not easily recognized from the general German population, so they were forced to wear a designator... the star of David.
When the evil one chooses "whites" as his enemy, it is far easier to identify those he has selected to be persecuted, those with the lower melanin content.
Below, see the common complexion chart ; where is then "white" and where is the "black" ! Just another way for the evil one to point out his prey.