One of the pins from the expansion slot carries signals to drive daisy chained WS2812B RGB LEDs (Certain Neopixels from Adafruit use this model ). Each RGB LED supports 24-bit color(16-million shades) and they can be addressed using a simple python command that accepts a 2D array containing color info for each LED.
A demo app was written using the ColorPicker button that's part of the PyQtGraph toolkit that's used extensively with the vLabtool. The button launches a QColorPicker Widget for each LED in the chain, and the colors are set using
#Set colors red, green, and cyan on LEDs 1,2,3 I.WS2812B( [ [255,0,0],[0,255,0],[0,255,255] ] )