Why not invest a little money in a portable compressor, an airbrush and some decent paint? Its not too expensive and its there for use for the rest of your life.
I have that already - an Evolution airbrush.
I even have a scuba cylinder with 1st stage and 2nd stage regulators, for portable airbrush use
But the damned thing takes such a long time to clean up afterwards that I don't use it unless the job is something worth doing right. Small touch-ups are not worth it - for all the masking one has to do.