O.E.
geolu, geolwe, from P.Gmc.
*gelwaz (cf. O.S., O.H.G.
gelo, M.Du.
ghele, Du.
geel, M.H.G.
gel, Ger.
gelb, O.N.
gulr, Swed.
gul "yellow"), from PIE
*ghel-/*ghol- "yellow, green" (see
Chloe). The verb meaning "to become yellow" is O.E.
geoluwian. Adj. meaning "light-skinned" (of blacks) first recorded 1808. Applied to Asiatics since 1787, though the first recorded reference is to Turkish words for inhabitants of India.
Yellow peril translates Ger.
die gelbe gefahr. Sense of "cowardly" is 1856, of unknown origin; the color was traditionally associated rather with treachery.
Yellow-bellied "cowardly" is from 1924, probably a rhyming reduplication of
yellow; earlier
yellow-belly was a sailor's name for a half-caste (1867) and a Texas term for Mexican soldiers (1842, based on the color of their uniforms).
Yellow dog "mongrel" is attested from c.1770; slang sense of "contemptible person" first recorded 1881.