stereo wiring for 2005 sierra

what are you trying to do?? if you pull out the factory headunit, to the lower right of where the radio sits there is a harness, that resembles the stock one going to the radio. if you are trying to do a amp bypass. if not the wires are

right front............light green + dark green -

right rear.............light blue - dark blue +

left front ...............tan +...gray -

left rear .................brown+....yellow -

if you take the cp holder out the one on the center counsole,. you can access these colored wires also, theyre twisted.