In Isaac Asimov's Foundation series, in several places he describes people having a "sallow complexion".
According to Collins dictionary:
(esp of human skin) of an unhealthy pale or yellowish colour
Unfortunately I'm not a native English speaker, and from the context I can't decide whether he means a very pale Caucasian or rather an Asian.
Not that it really matters for the comprehension of the story, but at first sight I thought it was a misspelling of shallow and this aroused my curiosity, now I have to find out.