91 mustang audio wiring codes

Hello, Im installing a new radio into an older 91 ford mustang, and I have come into a problem. I have 6 wires on the old connector (the one that connects to the original Mustang Radio) and my new stero only have 4 (but ones for power antena). My question is, which ones do I use? Im not sure what the color code for the original wiring is. The color of the wires are (in order from left to right)

Green (maby a stripe on it, cant remember)
(space)
Red (pretty sure the red is ground)
Blue w/ red stripe
Orange w/ black stripe
space
yellow w/ black stripe

I just cant figure it out. Shouldnt ground be universally black? Why do they have to complicate things so much... anyways, the new radio want the following connections:

+12 Battery Connection ( Memory +B)
Ground
+Acc Trun on

the forth wire is power antena, which i dont have. So does anybody know the wireing codes on a ford 91 mustang? Help would be greatly appreciated. Thanks!