Hm. I already knew the stock photography sites I use want photographs of people doing interesting things, but thank you for giving me an idea of what to supply them. Because I live in a neighborhood that seems to be majority POC, and there are kids, and there is a library nearby. And I could in theory pay the parents to photograph the kids and do the model releases and the whole nine yards.

In theory. Hm.

(Have you tried bigstockphoto.com, meanwhile? I know there are at least some photos of POC there, but not if there's anything like you're looking for.)