100 RGB LEDs, you can control 6 each with WS2803 with full color fade control, just need 17 chips if you don't want to muliplex them.
Available on e-bay (only place I've seen them in fact)
and only from 1 place in Niagara Falls, NY
Have read that WS2801 library is similar to what's needed for WS2803.
Or just wire up a chain of 100 of WS2801, and send out the 100 pieces of information needed for each RGB LEDs color based on your user input.
WS2803-preliminary-En.pdf (437 KB)