ya I am %95 percent certain that the Matrix has no switched 3v power. There is a switched 2V that we use to wire our chips up to, but that would only work for red LEDs with Vf=1.8V
you could use the non switched 3V and a transistor or a mosfet to turn it on and off with the 2v switched source. if you were to try a 3904 NPN transistor connect the positive LED to 3v, the negative LED lead goes to the Collector of the NPN (if you are using a resistor to limit current place it between the LED and the collector. Connect the Emitter to ground, and from the base wire a 1.5k ohm resistor to the switched 2V.
No garuntees that it will work, but it is worth a try. If 3904 doesnt work then we could try MOSFET.