blue is a pretty common color, if you want to, you could find blue hanldles that you could interchange with your old handles...(I currently have non ultimarc handle in my ultimarc joysticks.) I doubt it would be too expensive either.
If you post on the buy/sell/trade board, ask for blue joystick handles that would fit in your model of joystick...its worth a shot, that way you could get someone to check out the handles to see if they would fit your joystick before offering to sell them to you. you could also just take your chances elsewhere, ebay often sells misc. handles with no joysticks.
But painting does work, you should expect that over the years, you may need to do a new paint job, joystick handles can get a lot of abuse, and can be sweated on. Paint can wear off, It probably will take quite a few years before that happens though.
Good luck