This is a simple color ring with spinning colors. It uses Adafruit Neopixel and a Arduino micro but since it's very simple, the board model does not really matter.
Like on this picture, 5v to 5v, GND to GND and whatever digital pin to the ring INPUT. Here, I used pin 7.
You need to import the Neopixel library by Adafruit and then, upload.
See the VIDEO on youtube.
I used a Petri dish to enclose the Neopixel part, and a analog film tube to put the Arduino. I stuck a circle-shaped piece of paper inside the top part of the dish, so that the light gets more diffused, the idea being to use it a bicycle rear light :)