Christmas Snowman Tin (Single extruder multi-colour)

This Christmas container uses layering to produce a four-colour snowman tin using no special equipment and no mid-job filament changes. Here's how to print the white tin pictured. I strongly suggest you read all of this before printing. It's straightforward, but unusual!

I strongly suggest a layer height of 0.2mm, as that is what the layers are set up for. If you find that your slicer preview doesn't show the rectangular border around BlackST.stl, GreenST.stl etc. then lower your extrusion wi