One problem with printing stuff in color using typical CMYK printing ink, is that it’s often difficult to get the exact color you want. This color palette shows the color and grayscale range of the fullcolor prints offered by Shapeways. It contains a full hue gradient, to black, to gray and to white, as well as a black to white gradient, and the different base colors seperately. By scanning this color palette, and scanning another color on the same scanner settings, it should be possible to match the right color. The data available on the color palette should be enough to write a small piece of software that interpolates the entire color space in the print, and then get the required on-screen RGB for printing a specific scanned color in this material, which is something I’ll work on in the near future.
One thing that is somewhat noticable, is the slight yellowish-ness of the white color. Plotting the hue values on the hue side a bit, shows how yellow/green is very saturated, while inversely the printed cyan is not as saturated as the original onscreen cyan. Note that this plot is heavily dependent on scanner type and settings, so observations may vary.
If you want to see for yourself what the colors look like, you can get one too.