You can either paint the inside or the outside of the canopy.

The best way is to paint the inside of the canopy. That way the paint is protected from the exhaust residue.

If you do not have a steady hand or there is a lot of painting to do, you may be better off masking and painting the outside.

If you are painting the inside almost any paint for plastics will work fine. If you are painting the outside, use a fuel proof paint (ACRYLIC lacquer/enamel are fuel proof ), but test it on a scrap piece of the canopy first to insure it is compatible with the plastic (don't ask me how I know about that ).