hi Sebastian,
I have looked into the CK documentation you've sent. I think the iColor Cove EC is not DMX compatible, it's controller the sPdS-60ca is. The amount of channels this controller consumes is dependent on the number of fixtures connected. In the myriad of manuals and guides I have failed to find the DMX traits for the controller, so I assume it's just RED+GREEN+BLUE.
Please consider using the RGB fixtures in the 'Generic' library, they come in different sizes (1x - 10x). If some reason this will not work for your situation then please let me know; if you forward me the DMX traits and the number of Cove EC units your using I can create a file specially for you.
Maarten