What?
What has skin colour have to do with his ability to be a flying alien?
The whole point of his look was to represent the quintessential 'American ideal' of the 1940s and 50s of a tall, white, square-jawed male.
It no longer represents 21st century America.
What a load of non-sense, If you want a true DC black superman type then they can do Martian Manhunter. He's been done pretty well in Supergirl