The wiring chart is correct. Not sure how you're confused.

Best thing to do is to get a harness connector to put on the head unit and just read the color codes there.

You will find the front and rear leads and can simply run your own rear leads down to where you need them.

There's a write-up on my site that shows how I did mine (I didn't bother connecting the rear leads coming out of the head unit but it was clear to me which ones they were.

http://4x4icon.com/crossfire/pioneer_tuner/index.htm