I spray the paint in a small container, El Pato can, and a lot of it so it doesn't dry so fast. I also mix different colors to achieve a somewhat matching color for the touch up. If it starts to dry I mix a tiny amount of what ever they used in the paint, Xylene, Toluene etc. These are most likely synthetic quick dry enamel paints. Stay away from a lacquer based clear, it doesn't hold up fer schit.
The old school candy color paints are a tinted clear paint.