3D printers are great for homemade toys. But most affordable desktop machines can only print monochrome models. Mosaic Manufacturing, a Montreal-based startup, has created The Palette, a filament feeding system that turns a single extruder 3D printer into a multicolor printing machine. It acts like a bridge between your current printer and ever-evolving filament options. You can feed it up to four colors or play around with wood, steel or conductive varieties. It works in tandem with your machine, so it calculates and cuts the filaments needed for each element in a design before fusing them into one continuous string for your printer.