foobar with WS2812b strips addedUsing the same method most people use with the Let's Split, a short strip of WS2812b RGB LEDs were added to each half of the foobar.
VCC and Ground on each strip are connected to the broken out pads on the PCB. On the Master Left Hand side the DI (input) of the strip is connected to PB6. The DO (output) is connected to the unused connection in the TRRS connector. On the Slave Right Hand side the DI (input) is connected to the TRRS connection.
I used 60 per meter LEDs for 5 on each side here.
github. The pin the RGB strip is connected to and the number of LEDs is defined in the config.h file.