2007 Tundra Aftermarket Radio Install - Question

Evening,

Installing an aftermarket radio and am having some issues figuring out what one wire does. Downloaded this file from here - 2007 Tundra EWD EM04E0U.pdf

Audio System <Built-in Type Amplifier> - page 1 and 2. (page 33 and 34 in the PDF)

I am looking at connector K2 - pin 5 and what looks to me to be a peach colored wire. No where on the diagram above does it show pin 5 having a wire. All of the wiring harnesses on Amazon show no wire coming from pin 5 either. Any idea what this wire does?

Also, when pinning out the wires on K1, pin 10 has a wire in the harness but again, nothing shows on the diagram. Any idea what THAT wire does?

On a side note, I find it interesting that the rear speaker wires in the dash are a larger gauge than the power wire to the head unit!

 

The plot thickens.... Looking for solutions, I saw someone posted this photo of the right harness for the 2007 Tundra. Note it has the 5 pin wire. When you look up that part number on Amazon, the photo doesn't show that wire! -

$8 Metra 70-1761 Radio Wiring Harness For Toyota 87-Up Power 4 Speaker

https://www.amazon.com/dp/B0002BEQJ8

 

Bump! Any idea what that wire is?
I am looking at connector K2 - pin 5 and what looks to me to be a peach colored wire. No where on the diagram above does it show pin 5 having a wire.