Stavanger Makerspace hosted meetups to build a 4x4x4, RBG-LED, Arduino-controlled “charlie cube”. A charlie cube, originally designed by Asher Glick and Kevin Baker, uses a minimum of components and can be made very cheap by using just an Arduino nano.
Fellow maker Finn Espen Gundersen did a detailed write-up on that project.
If you are interested to make one drop a line to aerror funny character with an “a” futuredraht dot de
If there’s enough demand he can order a batch of PCB’s (10 minimum).