Early European explorers couldn't see any difference in skin color between themselves and the Chinese or Native North Americans, because there isn't one.
No difference in skin color between "Caucasian" and Asian people.
Citation: Norvang, et al. 1997. “Skin Pigmentation Characterized by Visible Reflectance Measurements.” Lasers in Medical Science 12 (2): 99–112. doi.org/10.1007/BF02763978.