4 wire color changing LED Xmas lights

[teenix]

I really have no idea of the LED lighting module, so guessing.

The controller box probably just changes voltage polarity to operate the white LEDs and back again for the RGB ones, it depends on the wiring though. To get different effects there might be a couple of LED strings.

If there is a wiring fault, I would expect all LEDs in the string to be affected not just a few.

If it is just a few, then likely they are just cheap components and they or their connections have failed.

cheers

Tony