Prints should start with black and change to white just above the 2mm layer, then back to black just above 3mm. Color changes are configured in the print and model files. On Prusa MK3S, I was able to print two coasters at a time.
The author remixed this model.
This model adds Treble and Bass clef coaster designs. There is also a matching tray that will hold up to six of the coasters, which is embossed with a single eighth note.