cave paint has some sun-blocking properties
For anyone curious about this, there's an article by the University of Michigan where the researcher (Raven Garvey) mentioned in OP's shared article is a professor and breaks down in details about it too. https://news.umich.edu/sunscreen-clothes-and-caves-may-have-helped-homo-sapiens-survive-41000-years-ago/
If you rather read the research paper: https://pubs.acs.org/doi/10.1021/acsomega.4c07476
For anyone curious about this, there's an article by the University of Michigan where the researcher (Raven Garvey) mentioned in OP's shared article is a professor and breaks down in details about it too. https://news.umich.edu/sunscreen-clothes-and-caves-may-have-helped-homo-sapiens-survive-41000-years-ago/