Namor has always been depicted of some ambiguous ethnic nationality, so someone of some color. But I never saw Asian, not early books, not later. Mandarin was Asian, Yinsen, Wong, Ancient One were Asian. Buscema had a distinct style with his faces, but Namor, similar to Mordo were ambiguous to me. I think it was just Bill Everett or Buscema's style....hell the primary style back then.