In Super Bowl LI on Sunday, the Atlanta Falcons are the home team. The NFC representative earns home team status in odd-numbered games, while the AFC gets it in even ones.
One of the supposed benefits of being the home team is that the Falcons get to pick which uniform color they want to wear in the game. The Falcons have chosen to wear their typical red home uniforms on Sunday, which means that the New England Patriots will wear their traditional road whites.
The Green Bay Packers play into this for a few minor reasons.