Audio Systems: line level converter, 2003 chevy trailblazer, chevy trailblazer

Question
I have a 2003 chevy trailblazer ls and i am installing an amp and subs in with the factory radio. my question is what are the colors of the left rear and right rear speaker wires right behind the deck at the harness? also what wire could i use as a remote wire for the amp?
any help is apreciated

Answer
IF your vehicle is a 2003 with the new rds radio  
you need a interface cutting the wires is not a good idea
http://www.oemautosound.com/pc-217-135-pac-c2a-gm24.aspx

if you don't have the rds radio you can tap on the wires

http://www.installdr.com/