Made this for kids in my athletics club, when I was making it I didn't know how to design for multicolor since I donť have a multicolor printer anyway so when printing I just added manual color changes in the slicer (at 1mm, 3mm and 4mm). 

Printed them in TPU at 0.2mm (hence the stringing) on PEY build plate from aliexpress for nice little stars on the bottom surface.

For custom initials edit the sketch with them in the fusion360 file.