COLIBRÌ: the driver for RGBW LEDs
Boris Landoni @ open-electronics.org designed COLIBRI, a board able to drive 4 color LEDs. He writes:
Recently some multicoloured power LEDs have appeared on the market and, differently from the more common RGB LEDs, they incorporate a white LED, as an addition: they are named RGBW (Red, Green, Blue, White) just because of this. They have been created because, even if in order to obtain a white light it is enough to light red, green and blue LEDs together (the brightness proportion as for red, green and blue will determine the white’s tone, that may be warm or cold), the addition of a white LED allows to obtain some much more “clean” white colours, in comparison with what could be obtained from mixing the three basic colours; it is moreover possible to use all the four LEDs together, in order to obtain a much greater luminous power.