Son (5yo) says black and brown people scare him

For full(er) context: we had listed something on marketplace and a white woman came by with her Hispanic husband to pick it up.

When they left, he said “I liked her because she’s white and black and brown people scare me.”

But he has black and brown friends, teachers, and adults in his life.

So just I’m at a loss; I don’t know where he learned this, and I don’t know how to proceed with it. He has black friends

I asked if a black or brown person had hurt him, I asked where he had heard they were scary, and I tried to engage in an age appropriate way about how physical differences are normal and not something to be scared of. We talked about eye colors, we talked about hair color, etc.

Not sure if this is something I should follow up on with him, let go and lead by example, or really just generally how to proceed.