Don't use VHT or high heat engine enamels... They're too brittle, and will eventually come off in sheets. Best results from Duplicolor or Krylon automotive exterior grade paints.

As with painting anything, preparation is at least as important as the type of paint, maybe more so.

That said, don't expect durable results from a rattle can. It'll look great, depending upon how smooth & steady you apply it, but it won't resist contact with hard surfaces... bike racks, walls & fences, zippers & belt buckles.
From bitter experience, I can predict that after a few months of use, the bike will look like it weathered a meteor shower.

My suggestion would be to deliver the frame to a car or motorcycle hobbyist who does some painting... There used to be a kid in my neighborhood, had a compressor, sprayer, and the required skills & technique. He'd hang moto parts up on his backyard clothes line and do a pretty decent job.

He helped me respray an old Peugeot bike frame, in BRIGHT General Motors yellow urethane, basecoat-clearcoat. Paint was leftover from some auto repair job he'd done. I gave him $100 for all his effort (he did all the prep work, too.)

The result was better than factory-new, with no drips, no orange peel, and only one or two tiny blemishes from flies that found their way onto the sticky surface (not visible unless I pointed 'em out.) I was quite pleased, and whoever stole that bike from me got one heck of a nice paint job.

So, rattle-can if you must, but seek a weekend car painter for far superior results.