The glass doesn't quite look realistic enough with the simple solid colors. It seems to break the details of the original skin.
Consider maybe making actual stained glass images? Something more like the way real churches/cathedrals today have it...And I'm not saying zoom in and draw a high detailed Jesus or anything like that. ...O.o; Heck, you could just go into Photoshop and splat some colors, in an organized fashion that is. The lower level smaller windows are nice, more of what they should be. I'm simply speaking of the larger ones.
(( one, but this one makes me feel all happy and bright 
