The files here are for an adapter to convert a single LED from a WS2813B LED striplight to standard 5mm LED dimensions. This adapted LED can then be used in standard mounting such as panels. Also included is a square 17mmx17mm panel mount LED adapter. These LED can be used to give a vast array of colors and brightness's and are very easy to adjust.
Also included in the model files is a test stand and details on how to use an Arduino to control 3 LEDs with potentiometer for RGB.

The download also contains more details, schematic, pictures, Arduino firmware, construction info, etc.

Also see the article describing this at EDN.com: https://www.edn.com/a-simple-full-color-upgrade-for-your-led-indicators/