since for Pope Zembla was roughly equal to Greenland, then Zembla must be a green land, an Arcadia. Arcady is a name often bestowed by Professor Botkin on New Wye, Appalachia, which also gets the epithet "green," and he quotes "Et in Arcadia ego,"for Death has come to Arcady in the shape of Gradus, ex-glazier and killer, the emissary of Zembla on the other side of the world. Green-jacketed Gerald Emerald gives Death a lift in his car.

The complementary color to green is red. Zembla has turned red after the revolution that began in the Glass Factory. Green and red flash on and off in the narrative liketraffic signals and sometimes reverse their message. Green appears to be the color of death, and red the color of life; red is the king's color and green the color of his enemies. Green is pre-eminently the color of seeming (the theatrical greenroom), the color, too, of camouflage, for Nature, being green at least in summer, can hide a green-clad figure in her verdure . . . 

And so on. She even mentions Sam Schuman's green room. The entire essay can be read here:

http://www.tnr.com/book/review/bolt-the-blue?page=0,0

So the thread, as Stan and others have suggested, is not so curious after all.

Jim Twiggs