You're probably thinking of the Himba tribe color experiment - which as it turns out, was mostly fabricated by a BBC documentary:
https://languagelog.ldc.upenn.edu/nll/?p=17970
Yes, I think this was it! Thanks for sharing the link. I had no idea that part was fabricated.
Yes, I think this was it! Thanks for sharing the link. I had no idea that part was fabricated.