You can do pretty much anything you want with the light effects in the editor, but you have to define every point yourself as far as I know. There's not really a way to introduce actual randomness, but you could easily build an effect that switches between several colors in succession. There is a limit to how many points you can include in an effect, but it's a big enough number that you can build some pretty complex sequences if you so desire. For a basic example of what's possible and some of the issues, I offer this link to a thread I wrote up a while back about adding a subtle shimmer effect:
http://www.saberforum.com/index.php?topic=38377.0.
I also offer the following example of how complex you can make an effect: the powerup lighting I created for a He-Man soundfont purchased from a vendor site. This effect is where I learned of the limit on number of points.
I'm really proud of how the lighting effects turned out, but sadly I can't share the font due to the proprietary nature of the sounds. Anyway, the point is that even amateurs such as myself can create cool things in the editor, you just have to spend some time playing around with it. Hours of enjoyable tinkering await you as you craft exactly the effects you want. Good luck and welcome to the fun!