Stock hot wire going into factory headunit

What color is the "power" wire that goes into my stock 6disc changer unit. (2006 access cab)

 

I believe its yellow, or blue with a yellow stripe.

 

Thanks guys, I was just trying to get my amp to come on only when my radio does. I had probed all wires behind stock head unit, with key on and, with key off. Still haven't found a wire that is completely dead when key is off and hot when key is on. Blue with yellow stripe is the one that i eventually tapped into.