Buick radio wires

Can anyone help with what color wires go to what thanks

 

Yellow, power from instrument panel/clock power.

Green and Black are speaker.

 

That may be a pre 70 B or C body radio. Are you intending to put it in an A body? If so, take a picture of the label so we can verify the fit.

 

Thanks, is the blue the ground

 

Blue *should* be rear speaker.

But no knowing what vehicle, its' getting into guessing territory.

Ground is facilitated by radio housing via chassis/mount .