Keep trying. You may not like it, but tedious manual masking is about the only way in your shots.
MTV huh? Cool.
The procedure is to create a matte that you can use to control your color effects. This is made more difficult because there was no pre-production planning for that kind of effect so the shot is not suitable for automated tools to create the matte. For example, here's what happens when you try and use Rotobrush on that shot. The colors are too similar and the edges too soft for the tool to work very well.
So at least in this shot things are not going to work. Another option for this shot would be to try and use AE's mask tracking. I added a little movement to your still image to simulate camera motion and tried AE's mask tracking. This is where a very tight mask ended up after just a few frames:
The results were better than Rotobrush but still would require a bunch of hand work. You may be better off using Mocha AE to generate your masks.
The last option would be to hand roto the shot. Because of the complexity of the shot, the size of your actors and camera movement this option would take a very long time.
Once you have a good matte for your shot you would set up the composition with the matte layer on the top, an adjustment layer below, then the footage on the bottom. You then apply something like Hue and Saturation to the Adjustment layer and animate the opacity of the adjustment layer to bring your effect in and out. Basically the shot would look like this but you would need a much better matte.
If all your shots are like this it's going to take you hours and hours to create the mattes. If you decide to go ahead with the concept it's important that you edit the piece in Premiere Pro before you start the effects work so that you won't be spending a lot of time on frames that will never be used in the production. When you do this effect on a shot only use one shot per comp. You'll go nuts if you try and do this to an edited project with a bunch of cuts in the clip.