Every Formula 1 team must run their cars with the same race livery throughout the season and must ask FIA for approval if they want to make any changes.
Every car must carry its driver’s race number which are permanent and drivers use them as long as they race in Formula 1. Only exception is world champion who can have number 1 if he wishes to. All other drivers can select numbers from 2 to 99, but not the number 17 as a sign of respect for Jules Bianchi.
Driver’s name also must appear on the external bodywork of the car, usually near the cockpit, and team’s name or emblem must appear on the nose of the car.
To help distinguish between a team’s two cars, onboard cameras above the airbox have different colours – on one car it is black and on another is fluorescent yellow.
FIA F1 2017. sporting regulations can be downloaded here.