Having the force fields colored by player wouldn't work right, because of how the diffuse colorization works -- it multiplies the source color by the diffuse color, and thus if your color is red, for instance, any white pixels in the force field graphic turn red. This is different from a hue shift (which can't be done quickly on hardware), which would give the effect you're actually wanting.
Glad the soundtrack is a hit, and it's definitely on iTunes, Pablo has full rights for the stuff with the soundtrack, so that's his stuff to handle.