Silly Headlight Wiring Question

Hey everyone. I apologize in advance if this is a stupid question. But I searched, looked at the service manual, google'd it, and still couldn't find the answer I was looking for. So, here it goes..

Our headlights have a single 3 prong plug that activates both the DRL/high-beam and the low-beam. I need to modify this plug and attach it to my battery harness for my HIDs. Coming out of the plug are a white, red and black wire. The red wire eventually gets spliced into a green wire - resulting in 4 wires. Now, the green and white wires lead to the DRL/high-beam, while the black and red lead to the low-beam. I'll be attaching the black and red to my battery harness.

Now for the silly question. Which wires would be the positive leads, and which would be leading to ground? Intuitively, I thought Red = positive, black = negative/ground. So that would mean green = positive and white = negative/ground also. What confused me is that the red and green wires are connected, and I know that the DRLs and low-beams aren't always on at the same time. That sort of lead me to believe that the red and green were actually common ground, and the white and black were positive:confused:

Silly question, I know..

black is the nigative and red is positive

I'll get you full details if you would like for the complete headlight harness by tomorrow