[font=trebuchet ms]Electrons are colour-blind. They don't give a damn what colour the wire is.

Use your Ohm-meter to trace out where all of the wires go, and what they do when they get there. I'm guessing that the silver wires are ground connections to the pickup frames, but you'll need to check that for yourself. You will have to remove the strings so that you can lift the pickups out of their pockets and see how they're wired up. Make notes on how the bridge is positioned (it will probably fall off without the strings holding it in place) and how the pickups are oriented. Draw up a schematic of the circuit as it is now, and then work out what changes you want to make. Double-check everything![/font]