There is probably some sort of safety requirement for lighted exit signs. So long as they use light that is safe for paper you should be ok, though I don't think green would be safe. The university I attended had red safe-lights in the darkroom, but there was a small room, more like a walk-in closet, for loading film on the developing reels. This was completely dark (no safe-lights) but was so small there was no mistaking how to exit.

Make sure you eat before entering the darkroom. In my undergraduate I took a photography class, and I became "lost" in the darkroom - enjoying it so much I always lost track of time. My jeans would be noticeably more loose by the time I left to return to my dorm room.