Let me know if you ever want to chat. This has always been an issue of mine for my son. My son at first was the only or few but now each year the school has become more diversified and he literally has friends from every background. He is 13. But even in the younger years I made sure to seek specific activities, play groups, etc of diverse backgrounds. It can be a catch 22 on either side of predominantly white or black schools. Keep checking in on his mental health.