Sundance audio wire colors

I am installing a stereo in my 1990 Sundance and I had purchased the 12 volt resource CD on Ebay for the wire color mapping of the OEM harness.  here's the 12 volt resource link https://www.the12volt.com/installbay/detail.asp?info=alarm&year=1987-93&make=Plymouth&model=Sundance&ID=18724&type=Stereo

my problem is that my 1990 sundance audio wires do not match this scheme.  I have found which two wires are the speaker connections at each of the speaker installation points on the harness, but do not know which is the + and - connections. 

Is there another/alternate wiring color scheme for the 1990 sundance audio system that anyone knows of?

here is what i have

1990 PLYMOUTH SUNDANCE 2DR COUPE 
 
 Audio/Mobile Video        
 WIRE  COLOR  POLARITY  LOCATION 
 Battery  PINK  (+)  RADIO HARNESS 
 Accesory  RED / WHITE  (+)  RADIO HARNESS 
 Ground  STRAP 
   THIS RADIO GROUNDS THROUGH A CHASSIS GROUND STRAP. 
 Dimmer  ORANGE / WHITE  (-)  RADIO HARNESS 
 LF Speaker (+)  GREEN 
 LF Speaker (-)  GREEN/ YELLOW 
 RF Speaker (+)  VIOLET 
 RF Speaker (-)  VIOLET / YELLOW 
 LR Speaker (+)  BROWN 
 LR Speaker (-)  BROWN / YELLOW 
 RR Speaker (+)  BLUE/RED 
 RR Speaker (-)  BLUE/WHITE 
 Amp Location  NOT LIKELY 
 Radio Security  YES