This is the machine that paints the cubes grey. Red is not really supposed to be in this part of the factory, as it has nothing to do with his job. He still doesn’t know what the cubes are, or where they come from, just that they don’t all start out as grey.
They are painted just because Black and White abhor color, like cartoon villains from the 80s. This isn’t because their ancestry. You see other black and white people later who surround themselves with quite a bit of color. It’s just something that is unique to these two.

As an engineer the way I drew those gears bothers me. I will have to do a much better job the next time I show this machine.