You could always do an under bed, under tank heater. That way there are no lights involved. It's better that way anyway. Just run the cord along the wall and then no one has any idea anything is even there. One side of the tub would face out, so the animal would be able to tell whether it's day or night, and then the other three sides are dark. It's perfect for ball pythons and their privacy.

Btw, did you know some apartments have rules like, "Small dogs and cats ok. NO SNAKES" ? When I was apartment hunting I saw that, and it was like, "are you kidding?" But I guess the only reason is maybe they had some larger animals escape in the past. I can see how it would be a scary situation for non-snake people. *shrug*