Trying to print something using multiple filaments with a single extruder? Can't quite dial in your settings and some prints didn't turn out how you wanted? I've been there and wanted to find a better way to help me get my technique down - enter the Single-Extruder Multicolor Test model.
This is a tiered 30mm long x 45mm wide by 45mm tall model to let you try printing up to 3 different colors using whatever plugins/techniques you're interested in (me personally, I found Octopi's Multicolor plugin to work very well) without ruining a model you care about.
Note: the physical pictures shown are of the protoype which was 15mm x 45mm x 15mm. I didn't like how small it came out so I upped the width and height to print out the words a little clearer. And for some reason the yellow filament plugged up on 1st layer of the change.