You've got things that emit light, that light should reflect onto the objects in the scene. There's an excellent tutorial on doing reactive lighting on DigitalJuice.com at the moment.
I haven't checked out the tutorial yet. Since this looks like it was done with a default emitter in Particleillusion, I've got a little experience with using PI. The way I am doing it so far is maybe a post "cheating way" in Vegas::
--- Reflective/ambient lighting or highlights can be done with a wise use of mask or masks of the scene feathered in the right places -- traveling centered out from and with the light source's path (effects in this case)..
I.e. I have a scene which a woman is in a lavender lighted setting. A warm, golden/orange light starts to emanate from her heart. As the effect grows, her chest and body progressively take on the colors of the effect.