Sallow means yellowish and unhealthy in complexion. A sallow face, sallow skin, look sallow.
It is always unkind, because it names a colour and diagnoses at the same time. Jaundice, tiredness and bad light can all produce it. There is also a tree called a sallow, a kind of willow, which is a separate Old English word.
1adjectivesallowYellowish and unhealthy in complexion.
“After weeks indoors, his skin looked sallow and tired.”
sallow is a quality of complexion.
Old English salu means dusky or dark yellow, from a Germanic colour root. The willow called a sallow is a different word.
Proto-Indo-European
*selH-
Proto-Germanic
*salwaz
Proto-West Germanic
*salu
Old English
salu
Middle English
salowe
English, today
sallow
From Middle English salowe, from Old English salu, from Proto-West Germanic salu, from Proto-Germanic salwaz, from Proto-Indo-European selH-. See also Dutch zaluw, dialectal German sal; also Irish salach (“dirty”), Welsh halog, Latin salīva, Russian соло́вый (“cream-colored”), and - through Frankish - French sale.
Etymology from Wiktionary, CC BY-SA