Metallic colors such as Candy Apple Red I can not mix myself in nitro, so I have to fall back to the vast range of acrylic car paints. However, for nitro feel and properties, the topcoat can be done with transparent nitro lacquer and for a vintage look with an amber or a brown tinted nitro lacquer.
If you want an extremely resistant and insensitive surface, you can use a 2K topcoat.