sallow

sallow \SAL-oh\, adjective:

having a sickly, yellowish color

"After several days of flying in space, the astronauts may look wan and sallow, so medical staff will put make-up on them to make them look ruddy," the newspaper said.
-- The Sydney Morning Herald, 2005-10-17

Actually, Thompson looked old and sallow, as he faced the cameras for a few seconds before hopping into a waiting GMC Envoy.
-- The Washington Post, 2007-04-19

Old English salo "dusky, dark," from Proto Germanic *salwa-, from Proto Indo-European base *sal- "dirty, gray."