Painting a 'candy color' - clear color over metallic- is very difficult. It's probably the hardest technique to do in body painting. If you spray the orange on in a wet coat it will pull away from corners, edges and panel lines, leaving light patches. Once this happens, it's impossible to correct. The only way to go is with lots and lots of light even mist coats, and don't ever let the paint get wet.
Don't polish the orange- give it a cover of clear and polish that. If you polish a transparent color, you'll wear thin spots in it- they will be easy to see an impossible to fix.