We've been able to change colors mid-print by either joining filament or following the end of one color with another. This enables layers of color. However, it doesn't help with spot colors on the same layers.I wanted to figure out a way to "register" the TOM so I could print a base and then selectively go back to different spots and prints colors after changing and flushing the previous filament. Since RepG will center a file on the virtual platform, if you have a common outer plane that doesn't print, then all elements can be centered and the registered to one another.Another problem is making sure the print head doesn't hit the previously-printed areas on its way to print another element. So, for this test, my business card seemed like a good example to prove the concept.The idea sort of worked...for the most part...but it still needs a lot of love and attention that might not make any of us want to try this again ;-)You have to manually zero the first change of color after printing the base. (Make sure to edit out the homing code.) Order of the colors is from bottom outer corners inward and up so print head doesn't travel into previously-printed space.For this design I imported nine separate .stl files (each having a plane in the file that doesn't print).1) print base only 2) Flush filament, load orange, and re-zero in the middle of the base, using the base's height as your new platform. Print the D. 3) After "D" finishes, do not move print head or re-zero. Flush and load yellow, and print the R. 4) Flush and load blue and print both Es. 5) Flush and load yellow again and print the N. 6) Flush and load gray and print the S. 7) Flush and load green and print the G. 8) Flush and load red and print the 1. 9) Flush and load white and print the remaining text.