Antennae wire and other wires for the stock stereo are listed below:
1995 Buick LeSabre Stock Radio Wiring Diagram
Car Radio Constant 12V+ Wire: Orange
Car Radio Ignition Switched 12V+ Wire: Yellow
Car Radio Ground Wire: Black/White
Stereo Radio Illumination Wire: Gray/Black
Stereo Radio Dimmer Wire: Brown/White
Stereo Radio Antenna Trigger Wire: Dark Green
Stereo Radio Amplifier Trigger Wire: N/A
Front Speakers Size: 5 1/4? Speakers
Front Speakers Location: Doors
Left Front Speaker Wire (+): Tan
Left Front Speaker Wire (-): Gray
Right Front Speaker Wire (+): Light Green
Right Front Speaker Wire (-): Dark Green
Rear Speakers Size: 6? x 9? Speakers
Rear Speakers Location: Rear Deck
Left Rear Speaker Wire (+): Brown
Left Rear Speaker Wire (-): Yellow
Right Rear Speaker Wire (+): Dark Blue
Right Rear Speaker Wire (-): Light Blue