Watch the video.
I first used Fusion360 to make an enclosure for this simple setup which consists of three potentiometers, an Arduino Nano, and a NeoPixel Ring which has 12 WS2812 RGB LEDs.
Originally I was planning to use an ATtiny85 to control the RGB but it only has two analog inputs but the requirement was three analog inputs so I used this Nano clone instead.
Well first, print all the parts.
Then connect all the things together using wires or you can create a shield, like I did.
From there, download and install the Adafruit NeoPixel library, and upload the sketch.
Here's the link - https://github.com/adafruit/Adafruit_NeoPixel
Thingiverse link - https://www.thingiverse.com/thing:4079529