I drizzled some 35% nitro on a test strip of Rustoleum -- but it had sat for over a month. Further, it was yellow and I've heard rumors that darker colors aren't as fuel proof. Further yet, I've heard that you have to use the gloss "protective enamel". Certainly the "flat black" that I used for the canopy of the plane got soft from fuel, although it seems to not be as bad now as it was originally.
So if you point it with yellow "protective enamel", and you paint yourself a good-sized test strip, and you test against the test strip before you fly, then eventually it ought to work.