You have a monocolor 3D printer and you want colors? You have a few options, but not all of them may fit into your budget.
The simplest approach is simply buy differently-colored filament. However, you’re still printing in one color unless you print multiple pieces in different colors and then connect them together. For example, imagine a 3D print of a car with a red body and black tires.
A second approach is to use a second (or third or fourth) extruder, each of which can potentially be loaded with a different color. This is increasingly frequently done, but results can be tricky unless all extruders are perfectly aligned.
If you really want actual RGB color, you have a couple of more expensive options to consider: One is the 3D Systems CubeJet, which retails for under USD$5,000. It can produce full, RGB color objects using a powder process. However, the objects produced are relatively fragile and require infiltration after printing with various kinds of fixatives.
Another more expensive option is the MCOR Iris, which uses a paper-cutting process to produce full-color objects. Colored patterns are pre-printed on sheafs of regular paper, which then are cut, glued and gradually built into rather strong objects. How strong? We have an MCOR-printed bottle opener that actually works - and it’s made of paper! The Iris costs around USD$40,000, though, so it may be outside your budget.
3D Systems’ new flagship color 3D printer, the ProJet 4500, prints full-color RGB objects using a more advanced powder process that doesn’t require infiltration. It’s available for around USD$70,000.
The new Objet 500 Connex3 from Stratasys can print using ten different 45-color /material palettes. If your color design can fit into one of their palette schemes you can achieve a finely detailed, brilliantly colored print. However, the Connex3 will set you back around USD$350,000.
And that’s about it for color 3D printing options today.