color codes should be standard for just about every headunit out there. I just finished putting in the replacement radio in my car. I can take a look when I get home tonight and put that info up here for you. (I am assuming that your headunit no longer has the little identifier tags on the wires?)
I'll see if my Google-Fu is strong today. I may be able to find you the proper color codes for the wiring.
Let me ask you this too...you say that you can see where the rear are hooked up. You should see an additional set of wires (2x2) coming out of the radio or the pigtail that aren't being used, no? Those would be the wires for the front speaker. Or am I to understand that you have those wires, but can't find the wires coming from the front speakers themselves?
In my car (which was seemingly bastardized ten times over before I got it), the passenger front was accessible by removing the glovebox. (5 or 6 screws to do that)