So when I was in first grade, we had a girl who was basically a token black girl in the class.
I always thought she smelled unusual, and I never figured out why.
Sometimes people would bring in the smell of their dog or cat or whatever horrible filth they rolled around in the previous day to class, but she was the one black kid, and it was really far off from the "me smell" baseline that I used (something like a mix between overbaked raisins and raw/cooking potatoes, btw. Don't know what I smell like now).
I've met other people who smell really weird since then, but for a while I just thought that was how black people smelled.
One of my (racist) druggie acquaintances suggested that it might have been lingering weed smoke, but having smelled that on people in the recent past I can say that's not the case.