[adventured]

Since you decided to dedicate your first ever HN post to that inquiry, I'll give you my personal reasoning.

Both black and white are very commonly lower-case. For example in the Bloomberg article, they refer several times to "black person's" and "black." I consider it incorrect to upper-case a racial identifier if you're not going to upper-case them all. I alternatively could upper-case Black and White, however I also consider that wrong, and borderline stupid (again, my personal opinion).

If I were referring to a specific national heritage, I would upper-case. Vietnamese American. Nigerian American. German American. And so on.

I also would not upper-case "a Tall American" in description of someone. A person that is an asian American is not necessarily from Asia, asian is their race. A person is not from "black" or "white" either. It's as ridiculous to upper-case asian in this use, as it would be to upper-case Brown Eyed American or Green Eyed American or "the Freckled American."

[meric]

There’s white people in Asia, peach people in Asia, light brown people, dark people, black people in Asia.

But then you wouldn’t call a black Asian a black person, he’d just be South Asian.

Therefore since your use of colours is tied to the location of the person’s ancestors, Asia referring to the continent, oughtn’t it be capitalised?