After covering myself with ink (and completely destroying the Red sharpie)  I discovered you can carefully take apart a sharpie w/ a pair of pliers.  You can then remove the plastic wrapped  ink reservoir, cut it open with a sharp blade and wrap it around the filament before it gets pulled into the ez-struder.
I secured it w/ duck tape which let me put it on and pull it off in various places - Multicolor!  Easy, inexpensive, but a bit messy. 
See the pic, colors used fuscia and baby pink on glow-in-the-dark abs.