Summary

These parts are used to convert any single color/ single extruder 3d printer to a 7 color system with no additional parts.
except some 3d printed parts and a few sharpie markers.

The parts are colored with markers between the layers.
6 colors are stored on top of the machine, the print head can take the right color from the marker holder and color the parts.

You can load any multicolor 3d model in cura like you do with multi-material.
A plugin (pencolorizer.py) will modify the gcode to actually paint the parts..

I use a bigger hotend so the stock parts didn't fit.
modified the pen holder to be placed a bit more to the front.

Here you can see a video of it actually working:
https://youtu.be/Vg7KW70APdM

A full tutorial how how to build this yourself can be found here:
https://github.com/Sakati84/3DPrintColorizer

hope you all have fun and please share your experience,