I had to explain to my son just yesterday why some people have different colored skin. He started the convo by asking about a young man we saw at the store with a prosthetic arm. Then it progressed to why people have different skin. They have been around african-american kids for most of their lives and never once even asked about the difference. I thought that was really neat, that it didnt occur to little children that these people could be any different from themselves, which is the right mindset to have. They have always just played together and accepted them without a second thought.