I designed a prototype PCB in kicad and then ordered a small batch of them from the great oshpark.com. I used interesting method to solder them, put the PCB on a standalone electric hotplate, move the components in to place with the aid of a USB microscope.

This actually worked, but proved I needed two cells to run all colours red, green and blue.

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Wired up to a simple sketch, to give some random colours.

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I have since improved the script a little to reduce the flicker.