I don't know if you're using Photoshop to do the color effects, but here's something I've found useful for simulating rays of light going through dust.
Set up a separate layer for the gradient or whatever you're using to make the light (the corona of the star, or whatever), then apply a "Pointilize" filter to it. Then, apply a Radial Blur, setting it to "Zoom" instead of "Rotate." Set the zoom amount to the maximum, and put the origin of the zoom behind whatever the source of the light is (this is a bit of a crapshoot with Photoshop, but a few tries will get ti placed right). And that's pretty much it. You'll end up with random streaks of light emanating from the center of the light source. Then you can set objects on layers above the light streaks and delete the parts behind it, to give an effect of shadow across rays of light. This is not to plug my own comic, but a
recent page I did used this effect for headlights on a truck, and I think it was rather effective. You can even do it more than once on different layers and pile up various gradations of color or transparency, to simlated differences in light intensity.
It's still a really cool comic, though, and I hope to see more of it soon!
--M