what i'm seeing here is a color inkjet print head rigged to dye the filament as it comes through based on some custom g-code. i guess this is similar to mosaic's idea, but taking a different approach.

if someone can make some thing like nicholas lewis's inkshield (http://nicholasclewis.com/projects/inkshield/) except with the ability to control color printheads, than this is totaly open sourceable.