BTW Erik, you say ledpanels are your businness. Are there any good books available on this matter?
Not that I know of.
And what about the hardware, I can buy red, green and yellow leds for about 0.10$/piece (±70mcd) true rgb ones are at least about 2.5$!!!!!!! Sure makes a panel REALLY expensive!
I am, currently, using 3 individual LEDs mounted close together, at sufficient distance it works.
Or are assembled boards cheaper? any hints on where to buy them? (preferrably in europe, I live in Belgium)
Try Ameli or Ugo Melli both in Italy. Steve, I believe has produced some, ask him.

Erik