Frame painting on a steel cross bike

[vanitypl]

I've got an old steel cx bike that I'm looking to use a bit more this coming season, but the paint job is a little bland and I'd like to touch it up a bit. Most of the frame painting info/questions I've seen online are about completely repainting the frame, but I'm not looking to strip the current paintjob, I just want to add little spice to the existing design by outlining logos and maybe introducing a new highlight colour.

What would be the best way to go about this and how could I make sure the touch-ups would survive multiple seasons of gravel and cx?
I'm not really interested in going to a professional as this is more of a fun project for me to kill time over the winter, more so wondering which paint/treatment combo would be the best for longevity in adverse conditions.

[yinzerniner]

Maybe go with something simple to begin with, like spray.bike. As always the prep will be the biggest thing, as you'll want whatever surface you paint to be sanded / we sanded down as smooth as possible and primed to accept the paint.

I've seen some decent results with their offerings.
https://spraybike.us/