Chandra; over on GreenComotion, got a bike paint owie, shown here.
One thing I learned from the Jaguar concours circuit, showing Felix, was how to make paint look its best, whether on the body or in the engine compartment. Bikes are a snap in comparison. One of the BEST things you can have in your collection of bike "fixit at home" stuff are tubes of appropriately colored paint. Less well known is that paint will also come in applicators that work a lot like felt pens - only with real paint. Just the trick when you notice a scratch 10 minutes before "rags down" arrives.
If my SRAM derailleur gets scratched, out comes the black paint pen and it looks like brand new again - and corrosion won't get hold of any bare metal. I can even match semi-gloss with a deft application of alternating black gloss and black flat paint. When corrosion got hold of the shifter bosses on the road bike, after proper cleaning & priming, the red paint pen made it look decent (though not perfect - these bikes are not for show, after all, but I'm after that 10 cents per mile target).
Wally World sells some of the colors. Gloss white, red, and black. A good hobby shop can get you set up with more. I suspect that if you're really A-R, you can get custom paint made up in a paint pen to match your metallic green or purple bike paint. Try here , here, or here to get started, though I've not tried these places. Or, if you're Rantwick - hot pink. If you happened to be someone named "Chandra," the stock Testors green, shown here, or the Sanford 63604 shown here; looks like neither would be an exact match, but either would make things look better while you search for a "perfect" color. Either's a bargain at under $4.
If, on the other hand, you're working with a Frankenbike, don't waste the money. Keep the corrosion away by riding so often that the rust doesn't have time to get hold of you. No need for therapy quite yet!