This work from the University of Calgary outlines a scientific approach for simulating the visuals of the Aurora Borealis. It is too computationally intense to run on PIC hardware, but the procedure can probably be simplified somewhat or else possibly it can run on an embedded PC system that talks to a PIC which controls the LED drivers. In any case the site, and particularly this Technical Report, is a good starting point and source of info about the simulation.

Simultated images of Aurora Borealis