Richard,
You suggested checking again with the manufacturer.
I went one better.
I set up the tube myself with direct 220V DV (no controller) and checked it out.
The tube has 4 wires coming out from each ends, terminating in a 4 pole connector (one male, one female). These are the uinput and output cables.
One of the 4 wires is a common and the other are for R,G,B respectively.
Aplying 220V DC across the black (common) and the Red, Blue or Green wires will cause the Red, Blue and Green LEDs to glow respectively.
Only interesting thing is that typically one would expect the common to be the -ve in the scheme, but in this instance the polraity seems to be reversed and so applying 220VDC +ve on the black and -ve on any of the R,G,B cables will cause the tube to emit R,G,B colours.
I have built a prototype DMX - DC dimmer and I am able to do global colour change on the tubes.
DM253