I use this little model for my bi and tricolor filaments.

It is a 20-minute print, allowing you to quickly observe how your filament behaves during the printing process.
The notches around the base are evenly spaced at 30-degree intervals. 

This feature assists in orienting future models on the print bed. By aligning the model with these notches, you can strategically position it to achieve the most visually appealing color changes.