That's why OC users like me know they can come here and get good information about their OC questions. I'd rather ask now before I set up the room than to later regret NOT painting the walls darker colors, etc.
On the other hand, if it's not going to provide a benefit, I might not go to the trouble and expense.
Unfortunately for me, airscapes' point about this being HT is exactly right. This is the only HT I'm going to have for a while because the $$ I had put aside for a HT remodel is going to help a family member in financial need. So if I can enjoy my viewing experience better for a year or two while I'm saving up (again) for my remodel, then it's worth it to me to do some painting.