Don't know about Krylon, but I do know that RustOleum is the same chemistry as Gillespie. I use RustOleum Rusty Metal Primer (the red version) under the Gillespie that I use to paint most everything in the yard. I did, however, paint a pair of M101 trailers with a "homebrew" OD using a formula that one of the guys on the old (defunct) BigElectric M37 forum posted that was to use a one to one ratio of RustOleum Hunter Green to Leather Brown. Those trailers are looking good serveral years after being sprayed and they get worked hard and live outside in the NC sun. The resulting color is a close enough match to most of my "factory" parts in OD that you can't tell the difference...
The same guy posted a variety of ratios for blending RustOleum and included some three color combinations including one that was very close to 383, but since I really like to use Gillespie 34052 (USMC Lusterless Forest Green), I didn't bother to save the info...
As for the original question, I would try to locate some color chips for Krylon in order to find a close color match, check Krylon's website to see if they do have a line of military colors, and would figure that it would be as durable as any consumer grade paint?