@Museek I think skin color is an easy way for simple minds to create a universe consisting of "us" and "them." Their focus is creating a place where they feel comfortable in a predictable little life with people around then who think, act, and in their mind therefore look like them. To make them feel better about their decision to push people away and force them to stay away (including excluding them from access to schools, churches, stores, etc. where they like to live) they invent "reasons."
They also use that criteria to scapegoat a group for their life's little issues, and as a group they can belittle to make themselves feel more successful. It's all based on petty tribalism. Skin color is just a convenient way for their inefficient minds to fill their need to belong to an important tribe.