These prints will align with one another to create a multi-color model with a single extrusion machine. You do not need to filament swap during prints, simply print each file “on top” of the next until finished. The “RED” file must be printed last. I recommend beginning with the White as the surest beginning. Using red filament for the black file and black filament for the red file will yield a Miles Morales variant.
The thin rectangles surrounding the print are registers meant to align the prints, not print themselves. Make sure you have z-hop enabled so the hot end doesn't scrape previous prints.
The author marked this model as their own original creation.