Well, I made it. 16 RGB LEDs on an Arduino, no LED driver used, just a single CD74HC238 demultiplexer. This is certainly NOT the way to drive LEDs, the Arduino here is basically just turned into a programmable LED driver that can’t do much else, but this was an interesting experiment. I even managed to get rid of ghosting — although now I’ll have to understand how the heck I managed to achieve that.
Also, now I’ll have to write the Instructable. Hopefully I’ll find a window next week to do it.