Those schools have a huge pool of people to choose from. If they use skin color as a criteria to ensure that the people in the schools are exposed to different

Those schools have a huge pool of people to choose from. If they use skin color as a criteria to ensure that the people in the schools are exposed to different COLORs of people in a society where COLOR has been used as a discriminatory tool, then I don't think that's unusual. I think that's actually fair, and I think educational institutions choosing to educate in that manner is exactly what they should do.