Cell phone radio mute for 2006 Xterra?

Does anyone know if there is a color coded wire for muting the Rockford Fosgate stero system on a 2006 Xterra for a hands free cell kit? Or is the only way to mute a hands free kit via the power line with the usual relay. Thanks!

I just spoke via emial to a tech. at Rockford. There is no "mute" wire, it has to be routed through the power line and relay.

Cheers:

Warren