Among the whites in the United States, it is only the reactionary ruling circles who oppress the Negro people. They can in no way represent the workers, farmers, revolutionary intellectuals and other enlightened persons who comprise the overwhelming majority of the white people.
That quote is from the Little Red Book.
That's the sort of thing I am looking for. Is there more up-to-date Chinese Thought on intersectionality or are they totally materialist?
There's the baizuo concept, but I understand that's more troll culture than theory: https://en.wikipedia.org/wiki/Baizuo
Sorry I don't know about modern Chinese works on the topic; but you may have luck searching for some of the relevant frameworks that are China-specific, versus talking about US minority relations, such as the relationship between Han and other national groups, or the 'minority nationalities' in China like have been written about by Mao in various texts such as a couple brief sections in ON THE CORRECT HANDLING OF CONTRADICTIONS AMONG THE PEOPLE. Going off of that angle you may have luck searching for similar phrases of and working from there, where there would predictably be much more focus and study and experience of theory and practice than you would find on US issues specifically.
Outside of China and in general, if you're also looking for specific analyses and political theory on white supremacy and colonialism, if you've not read Fanon's works, is very incisive and foundational texts on real-world colonialism and the psychology and inter-personal dynamics the colonial relationship, and the struggle against it, produces. Probably most important texts on marxist post-colonial theory, which also speaks to the superstructural --- ideological and identity and self-sense etc.; representations and phenomena which the material relations of colonialism, unfolded historically in white supremacy, produce. Wretched of the Earth and Black Skin, White Masks at least I speak to --- I'd not come across Toward the African Revolution until I found this archive collection of a few works incl Fanon.