The http://www.creationkit.com/Light_Script doesn't have any specific functions that you could use to change colour, so you'll probably just have to http://www.creationkit.com/Disable_-_ObjectReference and http://www.creationkit.com/Enable_-_ObjectReference a series of lights of different colours that are in the same place.
Cipscis
I have no idea how you're planning on getting the lights to cycle through different colours.. I have a feeling it's much more intricate than you're thinking it is. And if it was possible, I don't think someone's going to pop in and give you the code you need.
However it does sound pretty cool and I hope you can get it to work! An alternative idea which may be more rudimentary is to have all the different light colours and just enable/disable them one at a time. You should be able to set the speed. I just don't think there are enough distinguishing colours for light in the game.
Edit: Ninja by Cipscis himself!
Thanks guys. I'll go ahead and try that.
Oh, and I wasn't expecting any block of code. I probably should have specified, I was looking for a way to set the current RGB value of the light, like a "setAttribute("RGB", 30, 255, 120)" or something.