If they are steel or aluminum you can just get them powder coated. They make high heat powder coat paint. I could paint them for you (I have a powder coating setup) if your local it would take about 2 hours total. I would need the dimensions first to make sure they would fit in my oven.
If they are titanium, good luck. I powder coated a titanium exhaust back in the day and the paint just flaked off. Other people are having luck with high temp spray paint which leads me to believe they are not titanium.
You can buy the powder at ColumbiaCoatings.com - Best Powders - Best Service - Best Price!
and bring the paint to a local powder coating shop and have them do it for you. A 1/2 lb. of powder could do both cans and a shop would run about $40-$60 with you providing the powder.