Colour depth of display on Mini Display Cape?


I’m just checking out the Mini Display Cape and the documentation of used CrystalFontz display. It seems all parameters are already set, at least I could not find a possibility to set EXTC pin in order to write some own system function commands to display controller.

So my question: what is the predefined configuration of the display controller? And especially which colour depth is configured? RGB 4-4-4 or something different?