Need help identifying wires

I'm installing a MTX REq5 (sound processor to be able to add amp(s)) and I need help figuring out which wires are the + and - for the audio signal for the sub in the back of an 11 Access Cab. There are 7 wires here and I'm not too sure which ones are which. I attached a pic hoping that it will help.

I was thinking red and white, but I'm not sure. I was thinking black=ground, yellow=12V, blue/white=switch for little blue light, red & white= + & -, brown & grey I have no idea. Anyway that's just a guess I hope someone out there can help me out.

 

I've searched already and found a non-JBL wiring diagram that was accurate to the radio but it didn't have anything for the sub wiring...

 

Anyone? I've been searching online and couldn't find anything... I'm trying to finish up the project tomorrow if possible