Chloe

Proto-Indo-European root meaning "to shine;" it forms words for "gold" (the "bright" metal), words denoting colors, especially "yellow" and "green," also "bile, gall," for its color, and a large group of Germanic gl- words having to do with shining and glittering and, perhaps, sliding. Buck says the interchange of words for yellow and green is "perhaps because they were applied to vegetation like grass, cereals, etc., which changed from green to yellow."

It forms all or part of: arsenic; Chloe; chloral; chloride; chlorinate; chlorine; chloro-; chloroform; chlorophyll; chloroplast; cholecyst; choler; cholera; choleric; cholesterol; cholinergic; Cloris; gall (n.1) "bile, liver secretion;" gild; glad; glance; glare; glass; glaze; glazier; gleam; glee; glib; glide; glimmer; glimpse; glint; glissade; glisten; glister; glitch; glitter; glitzy; gloaming; gloat; gloss (n.1) "glistening smoothness, luster;" glow; glower; gold; guilder; jaundice; melancholic; melancholy; yellow; zloty.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit harih "yellow, tawny yellow," hiranyam "gold;" Avestan zari "yellow;" Old Persian daraniya-, Avestan zaranya- "gold;"  Greek khlōros "greenish-yellow color,"  kholos "bile, gall, wrath;"  Latin helvus "yellowish, bay," Gallo-Latin gilvus "light bay;" Lithuanian geltonas "yellow;" Old Church Slavonic zlutu, Polish żółty, Russian zeltyj "yellow;" Latin galbus "greenish-yellow," fellis "bile, gall;" Lithuanian žalias "green," želvas "greenish," tulžis "bile;" Old Church Slavonic zelenu, Polish zielony, Russian zelenyj "green;" Old Irish glass, Welsh and Breton glas "green," also "gray, blue;" Old English galla "gall, bile," geolu, geolwe, German gelb, Old Norse gulr "yellow;" Old Church Slavonic zlato, Russian zoloto, Old English gold, Gothic gulþ "gold;" Old English glæs "glass; a glass vessel."

1650s, "pale, wan," from Latin luridus "pale yellow, ghastly, the color of bruises," a word of uncertain origin and etymology, perhaps cognate with Greek khlōros "pale green, greenish-yellow" (see Chloe), or connected to Latin lividus (see livid).

It has more to do with the interplay of light and darkness than it does with color. It suggests a combination of light and gloom; "Said, e.g. of the sickly pallor of the skin in disease, or of the aspect of things when the sky is overcast" [OED]; "having the character of a light which does not show the colors of objects" [Century Dictionary]. Meaning "glowing in the darkness" is from 1727 ("of the color or appearance of dull smoky flames" - Century Dictionary]. In scientific use (1767) "of a dingy brown or yellowish-brown color" [OED]. The figurative sense of "sensational" is first attested 1850, via the notion of "ominous" (if from the flames sense) or "ghastly" (if from the older sense). Related: Luridly.