In "The Man with the Twisted Lip" the plot turns on the skill of theatrical make-up, learned in the "greenroom" of the theatre, where actors may relax, and if they are not important enough to have their own room, to apply make-up.
From my dictionary:
greenroom
n.
a waiting room in some theaters or concert halls, for use by actors or musicians when they are offstage
Indeed, Bill – it’s an old tradition that dates back to Elizabethan times or thereabouts, thought (despite the normal speculative guessing) no-one
really knows the definitive origin of the fashion.
In summation, what can be said amidst the speculation about the origin of the green room? Solely and indisputably, green rooms were in use in London theatres in the last half of the seventeenth century and perhaps earlier. There seems to be no connection with continental European theatres where the equivalent of "green room" is foyer des artistes, Konversationszimmer, sala degli artisti, salón de artistas, artistenfoyer, and artistfoyer. Why were they green? No one yet knows for certain, but theatre artists undoubtedly will continue to honor the tradition of the green room despite their general ignorance of its history.http://www.utas.edu.au/docs/flonta/DP,3,1,97/GREENROOM.htmlI like the fact that a tiring room came to be a rest-room :)