4 model

Free

Mixing 3 color in FDM printer with cura plugin

Thingiverse

Free

Geeetech A20M Simplify3D Profile 3 Color and 5 Color (mixing extruders)

Thingiverse

Free

Multifunction Filament Spool Holder for German RepRap NEO (colorizing and cleaning)

Thingiverse

Free

paint color mixing station

Thingiverse