Ok, I was messing around with what I would do with the background of this scene and took a quick stab at making fetts helm green while I was at it, trying to see if maybe I could add some helpful info for brash. Its still a quick version so nothing amazing. And the first CCed part has very ugly masking, so please bare with me. And I got alittle lazy, his antennas not done 8)
http://www.youtube.com/watch?v=ACeE2CWmxyI
It would still need some work on the specific coloring but what i did was the following.
I made 2 layers of a rotoed out Fett. The top layer was the original taken down to about 20% opacity. So that its just about see thru.
The second layer I used the "change color to color" effect, and selected to change blue to green. Youll have to toy with the options to have mainly the helm effected. Toss this under almost see thru layer, and you can come pretty close to the desired effect. I also chose the "brightness and contrast" effect to darken him overall.
Then under all that place the original background footage color corrected to your liking. This way ou are free to Correct the background to whatever you like
Total time worked on this one quick shot was around a hour using the roto brush in AE CS5. I couldnt imagine trying this with normal roto options.
If you dont have AE CS5, for sure go with one of the 2nd version you posted above. I like that one.