A multi-color, magnet-backed button, made for my kid's costume inspired by the “President Loki” variant as seen in Marvel's Loki on Disney+.
The thickness of the button is different on the top and bottom, so you can achieve all 4 colors with manual filament swaps. Black → White → Red → Blue.
2 pair of 10x3mm neudymium / rare earth magnets hold quite well. You can either permanently glue, or just use Sugru or hot glue to trap them for removal/reuse later. Just make sure you match the pairs with the button and backing before and during the magnet installation.
I intentionally made the holes big enough (11x3.25mm) that the magnets were clearly not press-fit, since there'd be so much variance between anyone's printers and sourced magnets. That said, it'd be pretty easy to measure and print some shims if you truly refused to use glue.
Pairs nicely with this Loki “tiara” and a suit!
The author marked this model as their own original creation.