Colorado's ban on indoor smoking is extremely broad. It even bans smoking by actors in the course of a theaterical production where smoking is part of the play. A coalition of theaters challenged this part of the smoking ban on First Amendment grounds. They lost. Today, the Colorado Court of Appeals affirmed that ruling on appeal.
The constitutional issue is a close one (the best analogy in support of the ruling would be that one can't use real cocaine in a movie about the drug culture). I'm quite sympathetic to the artists' plight and personally favor an exemption to the smoking ban for this narrow purpose, notwithstanding abuses of the exemption in states with a smoking ban and a theatrical purposes exemption. One way to address abuses might be to simply limit the amount of tobacco that can be used in any one performance.
Incidentally, a story in the Denver Post notes that the smoking ban in casinos which took effect in Colorado this past January, has been blamed for a roughly 4% drop in business in January and a 10% drop in business in February. I'm not yet convinced that this is the cause. Also, even if it is the cause, I'm not terribly worried about the economic well being of casinos, which aren't a central part of the Colorado economy either. Meanwhile, casinos are working on ways to faciliate outdoor gambling for smokers.