Those are tough lighting conditions. I didn't know switching to Adobe RGB could help with the color saturation. I know that can be really horrible in plays & concerts, and I frequently just put out B&W if a scene looks hopelessly oversaturated (occasionally, the oversaturation really makes the shot look cool, but it is rare). I'll have to give it a try.
When I shot Titus Andronicus a few months ago, the lighting was incredibly uneven all over the stage. If I wanted to shoot something on stage left, I'd have to quickly boost my ISO, and then bring it right back down as soon as I wanted something on center stage. I never trusted the in-camera metering, as the lighting was all over the place. By the time the 2.5 hours or so were up, I had about 5k photos and my fingers physically ached from holding down the shutter button and continually flipping settings. I've had many situations where I've shot roughly the same number of shots in the same amount of time, but this was the first time I had ever suffered shutter-button fatigue.