I love these neopixel rings from Adafruit, but they can be hard to attach to things. I used this design to allow the 16 LED ring to be attached to any flat surface using an M4 bolt and nut. It also includes a diffusing cap(needs to be printed with clear or opaque PLA). Printing the windows inhibits each individual LEDs color from bleeding into each other(so its optional).

I developed this using onshape because it's free and collaborative. Here is the link for anyone who would like access to the document.

https://cad.onshape.com/documents/6dad4ecb59a323e1085c33e8/w/136db225ac22febd6d8bfc53/e/68d26f5ce5a62f0732c02878