Grey    Front Right +
Grey/Black          -

White Front Left    +
White/Black         -

Purple Right Rear   +
Purple/Black        -

Green Left Rear     +
Green/Black         -

Black  Gnd

IIRC Blue was for the power aerial
& Yellow & Red were power 1 permanent & 1 was Ignition powered.

If your still using the stock bose speakers they are only 2 Ohm  and
powered and you need something like a Peripheral VEN 4/4.5 adjustable line
converter that came with my car.
Failing that I think you'd be better off replacing the speakers
with some decent units at the same time.

HTH