Have you tried a professional paint store for matching? In my area, several paint supplies can match anything you have. You'll have to use a "re-useable" aerosol sprayer and spray gun but you'll get good results with proper prep. Look for a Benjamin Moore or Pratt & Lambert distributor.
Thanks, that sounds like a good next step! Now that you mention it there's also a Sherwin Williams nearby that handles automotive paint. Time to make a couple phone calls...
The related question is this: Removing the paint will means removing, and replacing the tank graphics. Is there an aftermarket place that everyone goes to for these items?