trying to tap into the rear speaker wires

I have a 2011 Toyota tacoma and am trying to put a speaker box in. I am gonna tap off of the wiring for the rear speakers, but am in need of the wiring layout for the factory head unit to make sure I get the correct wires. Does anyone have the wiring layout for this head unit or one like it?

Your speaker colors are red + and white -  for the right, and  black +, yellow - for the left.

What kinda speaker box are you tapping to your factory radio? most of the time they are not stable at lower ohm levels and have no protection from burrning up! If your going to put some kinda 6x9s in and unhook your factory speakers thats fine or if your putting a LOC in to add an amp to your factory radio you should be fine also, but I wouldnt "add" a speaker box to your radio.