I was thinking about using some acrylic colors to do the same, but I would be using black or white instead of gold or silver. I don't know how well this would stand up to heat, moisture, and vibration over a long period of time.
If you are doing a period correct restoration this may not be good enough, but if you just want to get some color then it may be ok. I've seen some pretty interesting uses for acrylic paint, so I know that there are additives that you can use to get it to do what you need it to do.
Golden Paints makes a ton of paints and additives. If you have an airbrush, you could use some of their "Fluid Colors" and the airbrush to apply the paint. With a high gloss additive it may give you the effect that you need. You could do the same thing with a brush if you don't have an airbrush.
http://www.goldenpaints.com/products/color/fluid/fldirid1.phpIf you wanted to go this route, there are articles on the Golden site to tell you how to use the paints. Or just find a local art store with a staff that is knowledgable about this paint and the additives.
Then again, there's always that $4.69 can of gold spraypaint at Home Depot