I assume you mean the Non-Mach head unit 2003 wire colors, because with the Mach 460/1000 units, the head unit only drives the tweeters.
The Black/Pink wire is hot only in the Acc or Run position.
Red/Blue is hot in the start position.
Violet/Blue is hot at all times.
Left rear speaker: + Gray/Blue, - Tan/Yellow
Right rear speaker: + Orange/Red, - Brown/Pink
Ford does not show the remote trigger wire in the diagram, because the standard radio does not use it. You might have to remove the radio and probe the rear connectors with a voltmeter, with the power switch On and Off.