After the initial thrill of 3D printing wears off, one begins to look for possible improvements. One of the most sought-after improvements is the ability to print color objects. We don't mean "a" color, we mean "many" colors. Since plastic filament comes in only one color (except for that elusive Tartan filament we were looking for the other day), color printing is kinda difficult.
But there is hope! RepRap team members have been experimenting with methods of mixing differently colored together to create extrusions with unique pigments.
So far they've learned that they need a "stirrer" embedded within the extrusion to ensure a consistent color. Experimentation continues, but eventually they'll nail the process. After that, we suspect color printing will quickly emerge among the 3D printer kit manufacturers.