89 300 SE Wiring Diagram
 

Ok, so I got a new radio. Already took the old one out, and I understand that there is no wiring harness for it. I have found about 3 wiring diagrams for it, but I do not understand them at all.

On the one, the colors are: yellow/black, white/black, red/black, green/black. Does this mean that they all share the same ground? I have hard-wired a lot of radios, and I've never seen anything like it.

I'm sure there are plenty of you who have had to do the same thing. Please, tell me how to wire this damn thing!