I started with this illustration and made a number of changes, then designed a badge with it.
The badge has a front and back part, with the circuit between the two. The LEDs shine through the paper as well as out the sides. A paper switch with conductive tape and a paper clip is used to turn it on and off.
This badge uses a red LED, blue LED, a CR2032 battery, and some Maker Tape. There’s a full-color version as well as a black & white version you can color and decorate as you see fit.
I’ve got a few more badge ideas in the works, but if you’ve got an idea for one, let me know!