Well I have looked around and have yet to find a 3MM RGB of any pin configuration, though I may be looking in the wrong places.
For 2 pin multicolor I mean 2 colors and anything in the middle e.g. red, violet, purple, blue
or green, yellow, orange, amber, red, and so on.
They are actually two diodes connected in antiparallel, so an inversion on polarity will turn on one of the two primary colors, a square wave signal will give all the shares in the middle depending on the duty cycle.
This needs a bit of additional circuitry, but nothing being rocket science