Every language has some ridiculousness. Like how in English, we "go to the bathroom" in the middle of a desert -- as though English-speakers were all so proper, we can conjure cubicles complete with plumbing in the least likely of circumstances.
In French, though, my favourite category of bizarre are "words for ordinary things that seem to belong more properly to an HP Lovecraft story." Like "mal de mer" ("seasickness," but literally "sea evil"), "fenêtre de guillotine" ("sash window" but actually "guillotine window"), and "nécrologie" ("obituary" but literally "word of the dead").
Of all these, the winner, hands down, is "abat-jour" -- "lampshade."
The "abat" part is from "abattre" -- which once meant "to throw down" but generally means "to slaughter." This is the "abattre" from "abattoir" -- "slaughterhouse."
"Jour" meanwhile, means day, but poetically "daylight" or "dawn." The sense was probably originally "throws down the light" but it now reads more like "That-Which-Slaughters-Daylight."
I picture "That-Which-Slaughters-Daylight" as a twenty-foot-tall hulking demon, horned, bearing a scythe, that could only be summoned at a crossroads on a new moon, with just the right ritual from the Nécrologie. It would also be wearing a lampshade, to remind itself of its humble origins, but it would be a very scary lampshade. Probably something with skulls on it.
Context thinks the Colour of the Lampshade will be from Out Of Time. (QWP)