Mine and Wire's (@wireengineer on Twitter) DEF CON 27 Indie Badge. I (TwinkleTwinkie) designed the badge, purchased the components and assembled it, and Wire did the Software that makes Arc Badge work and the bulk of the Kicad design work.
Hindsight being 2020 I would have done this badge significantly differently if I were to do it over again. For one the RGB LEDs we used weren't as bright as we hoped and in fact are being overvolted to 5V to get the brightness we needed out of them. Some people speculated that they could swap out the resistors to make the badge brighter but the only two sizes being used for the LEDs are 10ohms and 47ohms respectively. Those are the lowest values they can safely be without burning out the LEDs.
If I did it again I'd use 5050 Addressable RGB LEDs. For one they're already 5V so you're not overvolting them, and for another they're significantly easier to design around. So why did I stick to the 3528 we used? Well because I had already bought the LEDs and had literally thousands of them so I had to use them and in the end they were good enough. The other reasoning being that Addressable LEDs have their own issues and are notoriously difficult for hobbiest to rework.
So if I were you and I wanted to make my own Arc Badge I'd take the files you find here, figure out what's what and program your MCU of choice and make your own bottom board.