Hmm I guess it may not...just found some more info here if you hadn't seen it: Ford Ranger Radio Wiring Diagrams
That page only seems to go back to 1990 though...but it shows different colors for different years. I guess maybe I just got lucky lol.
What color are the wires you're looking at? Is there currently a stereo installed? Maybe somebody that actually knows what they're talking about will speak up also heh.