Using a QT Py rp2040 and Neopixel 24 I have made this fully controllable RGB ring for inside a PC case. It is powered and controlled by USB C and is mounted with integrated magnets.

It retains its last state so if you want a specific colour at any given brightness, it will remain that way until you manually change it which can be done in the offline web app which is included along with the firmware that should be uploaded to the rp2040. The web app is some simple html code so nothing to install.

Connect Data input on the Neopixel to A0 on the microcontroller.

Print base layers in clear petg or the whole thing if you want.

The base design for this is my microscope ring led so see that for wiring and other details i might have missed.

LEDs - NeoPixel Ring - 24 x 5050 RGB LED with Integrated Drivers

Microcontroller - Adafruit QT Py RP2040

Screws - M2x8mm hex

Magnets - 3x6mm