People are very dumb about lighting in a theater - which I think is a huge mistake.
They are concerned about painting - sometimes - which is a good thing. Your question is great, but has a fairly simple answer... The darker the paint, the better! Don't forget that all surfaces in the room should be dark, this includes walls, carpets, furniture, and the ceiling!!! People will do everything but the ceiling and think it's okay when they are completely ignoring 20% of the reflection area.
Back to lighting...
Congratualations! You've now created a black hole of light in your theater - how will you light the space so people can actually see when you want them to? Or when you need to work on gear, or clean the room?
LIGHTS, LIGHTS, and more LIGHTS!
12-20 lights is not an unrealistic number for a 12x15 theater. Using highly directional recessed/spotlights zoned into multiple areas along with added accent lights you can really add a lot of light to the room with minimal impact on image quality. Most of all, when the lights are turned way up, you can actually see your way through the room and don't have any dark corners which make the room feel cave like.
Take a look:
http://www.avintegrated.com/lighting.html