Radio wiring for 1988 240

[niko.hoskins]

I removed what I believe was the stock radio a while back when it just crapped out on me (one speaker flickering in and out, tape deck eating cassettes, too much static in the radio). I have another radio which I believe uses a standard wiring scheme. My problem is in trying to match it to the wires hanging out my car. I've managed to determine a few of them with a meter but the rest are a mystery to me at the moment:

Red: power antenna
Black: ground
Blue: +12 V switched
Green: +12 V unswitched
Yellow
Orange
Brown
Gray
White/Blue
Blue/White

When I take any one of those remaining wires and connect it to the Left-Front negative on my radio I get sound without needing to connect anything to the Left-Front positive lead. This isn't the case for my Right-Front negative lead but that speaker may also be dead. Any help would be great, has anybody else seen this particular wiring scheme and know what they correspond to?