These are actually the toilets.
I dropped a colored gel when I was inside popping the flash.
As I forgot my flashlight that night I had to look for it in the short lightflashes of the flash that where so bright that they were more blinding then usefull. After a while I found the Gel standing up against the wall, a place where you would never look for a colored gel that has a thickness of no more than 0,1mm.