westfw:
So I bought some from Amazon and cut off one of the LEDs for testing...Standard RGB configuration - common anode, with the anode being by the obvious green dot. You should be able to drive them from Arduino PWM to all sorts of color combinations. (All the LEDs are in parallel, so total current consumption is likely to exceed that allowed on an Arduino pin. You'll need some sort of driver.)
I'm sooo glad I found this thread and I'm not the only person wondering about this. I'm in a similar situation, with wanting to mod possibly the exact same string of RGB LEDs (it sure looks identical), so this info gives me a good starting point.
Does anybody know of any good guides online for how to wire it to get the extra power, thought? I'm planning on powering 14-16 of the LEDs, so the board's total power probably isn't going to be enough. I've seen guides for powering 12V strips (usually common anode, as westfw on here figured out this string uses), using transistors and what-not, but none using a setup to power LEDS like this, which I assume are running on 5V? (I can't quite tell if each LED has a built-in resistor or if the voltage is reduced before going down the string).