from Dr. Bill [wwh]

How about grisette for grisaille?

M-W: Main Entry: griˇsette
Pronunciation: gri-'zet
Function: noun
Etymology: French, grisette, cheap unbleached cloth, from gris
1 : a young French working-class woman

There is a second M-W meaning for "grissete" which I would post without hesitation if this were my post, but it isn't so I will leave it to those who may be curious, to find it or not, if their curiosity is piqued or pricked and they want to take a peek. [This is a gray area for me.]

http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=grisette

Hint [from me]: There are ladies of the night, and ladies who only practise at dusk ['cause they have to get up early in the morning to go to their regular job].

You could call these ladies "ladies of the dusk". But the areas where they practice at dusk are not "grisaille". They are "rouge". [So they're easier to find. :) ]