Getting Dope other than clear is somewhat difficult locally for me. 

I have used Rustoleum "painter's touch"
purple
white
yellow
light blue

No problems except in the motor mount areas where raw fuel might collect. This was behind Cox bee engines.  When the engine was removed after several flights the color was lighter and would transfer slightly to white paper towel.  The color I was using was yellow on one airplane (crashed) and light blue (engine swap)

I have used Rustoleum "Stop Rust"
white
yellow
red
brown
blue

The results were similar, but there was less discoloration behind the engine after several days of flying over a couple weeks. This was with yellow.

I have used Rustoleum sandable automotive primer as a base coat.  I have also used white as a base coat.  The colors need about 48 hours to cure prior to sanding or the sandpaper clogs immediately, while the sandable primer can be sanded after a couple hours.

The cure time was more than 2 weeks as when fresh fuel (SIG Champion 25%) is put onto any of these colors after only a few days the color bleeds.

I would recommend taking the clear, painting, sanding, etc. the desired number of coats and letting it sit for a time (2 weeks) then puddling raw fuel on for an extended period of time, say an hour, then see if it resists.  Scrub it with paper towel and see if it feels gummy.

I have also tried Minwax polycrylic as a base coat to seal the wood.  It seemed heavy when I was done.  I have since read that instead of sanding denatured alcohol can be used to wipe off the excess after it has cured to clear.  I have not tried this yet.  I had no problems with the Rustoleum sealing the Minwax polycrylic. 

Phil