It's been a while since I wired a 1g, but I believe one goes to the speaker in the door, and the other goes to the speaker in the dash. I have a print out of which is which, but it is at home. You should have a couple sets of wires the same color... just tie them all together.
Edit: This may help
http://www.vfaq.com/mods/wiring-1genplug.html
Now that I think of it. The two wires of the same color were for the dash and door speakers. Respectively connect them to the gray, gray/black, white, white/black from the back of the new radio.