Back when I was painting my race car, I got all of my supplies from a local PPG automotive paint dealer. I got to be good friends with the counter guy and one day he told me "sure, we can put any color you want in a spray can for you".
It came in handy when I was painting my roll bar, there were some places that were difficult to reach with a spray gun not to mention there would be large amounts of overspray. The spray cans worked perfectly. I haven't been back to that store in many years, but check with your local automotive paint suppliers, I'm guessing many of them offer spray cans as an option.