I wouldn't paint them.

May i ask how you've cleaned them?

I'd have to second the "don't paint them" theme here. The reason you are seeing the multi-color copper thing is that in some spots, the plating has worn down to past the chrome/nickel plating. This can happen from normal use, or from cleaning with something too abrasive.

My technique for cleaning lug screws is pretty simple. You'll need a drill (i Use a drill press) and some 000 steel wool (very fine). I place the lug screw in the chuck of the drill, threads down. I then run the drill while holding a piece of the 000 steel wool against the lug screw (you can wrap it around the screw as well) and gently apply pressure while running the wool slowly up and down the lug.

This removes any rust and crud but doesn't dig too deep into the plating. You can also run the wool through the threads to remove a lot of crud.

Wipe the lug down with a clean, dry cloth and if you wish, go over the lug with a metal polish (I use Mothers metal polish myself).

If the screws are too far gone and there's little or no plating left, I just clean them as best I can and use them as is. It may take away from the look a bit, but I think it's better to keep them as close to original as possible.

In my opinion, a lug screw is not unlike a guitar tuner/machine head. They wear out and eventually need to be replaced. Nobody wants a 59 Les Paul with "original tuners" that are broken/slipping, if you follow me.

Yeah, I agree. Don't paint them. Just clean them up. It's MUCH better to have some splotchy, ORIGINAL lug screws than it is to paint them or to replace them with new, shiny ones. In fact, if I saw a drum that had painted lug screws, I wouldn't consider it as an asset to the looks. Paint would look tacky to my eye.

Ludwig didn't ever paint any black did they? I have a drum or two with some black lug screws, which I figured a previous owner had painted.