Grumpy_Mike: 12V, look at the PCB at the cut points. It says 12V on the web site, did the ones you get say 12V as well.
With this system all three LEDs within the cut lines will show all the same colour and will just look like one LED to the software libiary.
Thank you for your fast reply! Would this mean that the current is 20ma (for each color) for every group of 3 leds, or is it still 20ma for every led?
EDIT: The answer to my question is yes, 18ma for every group of 3 leds.