Painting in progress, before attaching the floor.
Notice the red tinge on the XPS substrate. This is actually the second time painting the same piece. The first time around I brought the walls up to precisely the same state as you see here—black foundation with grey drybrushing and some beige stones—and then I tried to airbrush on the coloured portion of the lighting effects. My paint wasn't thin enough, I got a little blockage in the airbrush, and suddenly the red was far too strong. Damage done, I continued applying brighter colours with similar coverage, hoping to fix the problem with ink washes. I failed and had to start over with a fresh coat of black.