R2-D2 has some fancy lights in his head, but here with the 40% scale they resulted to holographic stickers instead. I might change that with some fibre optics (lichtleiter for ebay) or replace it with an OLED - not sure yet! both displays come together to 225 LEDs.

LED system: 

http://2geekswebdesign.com/astromech/lighting-up-the-dome-part-1-building-the-teeces-3-2-logic-display-and-psi-system/