There are any number of "style" manuals for writing - those of us who have labored through term papers, a thesis, a dissertation, or an article for publication understood that if our efforts were to be accepted by our "evaluators", be they advisers or editors, we had to follow the style manual that our evaluator preferred or specified.

The style in question, chosen by some of the publications in the country, isn't accidental - it follows the old dictum that he who controls language ultimately can control thought. Personally I tend to use a small "b" or "w" when black or white is used as adjective modifying a noun. When Black or White is used alone as a noun in reference to a person I capitalize both, just to be perverse, because the "right way" smells to me like an effort at ultimate thought control, and because the upper case "W" is harder to write off as "oversight" than using a lower case "b", and is just a little more "in your face" to the woke.