I have used only their standard colors and have not inquired about custom colors, I fear the price may be high.

I have had good luck with adding cross linker to the color paints and flying without clear coating, and adding cross linker just to the final clear coat coats. System 3 clear adds a nice gloss or satin finish depending on the clear you use and works good over color tissue for an old school look. Fuel resistance is very good either way, best if you let the paint fully cure for a few days before flying. I think System 3 is a very good and SAFE way to get a fuel proof finish on a glow plane but it does require a little different technique than solvent based paints. Best part is the thinner (water) is almost free.

Automotive paints are pretty toxic so I avoid them.