Puzzle I saw on social media recently. I didn't see a model available so I made this version. Tolerances are a bit loose to ensure fit.  

Gcode file is for a 0.5mm nozzle!  It has a color change at ~58 minutes and again about 3-4 minutes later.  Gcode was modified to keep the perimeter solid with only the interior with the color change. See Photos.

Good luck!