Thanks for reading. Black with a capital 'B' refers to people of the African diaspora as a culture, which makes it a proper noun subject to capitalization (i.e. the Hopewell culture), whereas white with a lowercase 'w' is an adjective that describes a particular status (i.e indigenous people).
There’s certainly more than one school of thought on this issue, and many critical race scholars much smarter than me have weighed in on your capitalization concern.
As a copy editor, I’m sure you would have a unique perspective on this after reading the research currently available. If you decide to write about this, be sure to let me know I would love to read it.