When specifying a pixel mappable fixture, you can set up the geometry references and do the positioning just fine.
There doesn't seem to be a way to specify the "Geometry Reference" that a set of RGB channels relate to.
Occasionally it seems to try to configure them, changing the RGB attributes in the list to Pixel1_Color_Add_R instead of the default "Geometry Name"_Colour_Add_R.
I have not managed to reliably make this happen, and can not seem to get another Pixel defined with another RGB attribute set.
Am I missing something here or is this just incomplete functionality?