Forgot to post the board I referenced above:
http://www.crossroadsfencing.com/BobuinoRev17/
If you want it matrix-like, RGB complicates that. With MAX7219 & common cathode devices, you can connect up two per columns and use a board like this to connect them up easily, drive 16 LEDs per board, and daisy chain 4 boards for 64 LEDs.