In the '05, V6, when removing the dash panel that covers the stereo mount, there are three harnesses to remove at the top of the panel. The one on the passengers side is the airbag indicator. The middle is the cigarrette lighter.
What is the one on the left (drivers side?) It does not hook up to anything except an empty slot in the panel in my 05.

 

That would be for the My Color button to adjust the different settings on the instrument panel.

 

I wonder.....can the MyColor option be accessed by simply adding the interface(button), or are there more components needed for the option to work?

 

I believe there is a write up on someone doing it on here but you need a whole new guage cluster for the My Color.