Unless you opted for a coloured gel coat on your car, you will need to get the car painted. All modifications to the body work standard should be complete and all ideally components been trial fitted (e.g. lights).
As the car is constructed from fibreglass the surface will need to be prepared. If not already done remove the flash lines from the body mould (e.g. top of wings) with a hand file and sand paper, be careful not to over trim the flash lines. Most painting firms can offer to do this on your behalf.
Once the body shell has been smoothed out it needs to be primed with a plastic etching primer. Once etch primed, painting is as with any other vehicle.