The NFC is the designated "home" team in the odd numbered Super Bowls. Having home field designation, the Cardinals will have a choice. Tradition would suggest they'll be wearing red and the Steelers will wear white.
Update:
According to the Pittsburgh Post Gazette, the Cardinals have indeed opted to wear red and the Steelers the white jerseys in which they won Super Bowl XL.
Factoid: The Steelers were the "home team" in Super Bowl 40 however they chose to wear white.
The Steelers were the road team in Super Bowl XLIII and wore their white jerseys.
The Steelers wore their white uniforms. The Arizona Cardinals were designated the home team for Super Bowl XLIII. They chose to wear their red uniforms. That forced the Steelers to wear their white jerseys.
The NFC was the home conference in 2009. Arizona had the choice of what color to wear. Pittsburgh ended up wearing their white jerseys.
Red and white.
Black.
black pants and black jersey with regular helmet
Green Bay will be the home team. The Steelers will wear their white jerseys and the Packers will wear green jerseys.
From the color of their jerseys. Chris O'Brien, who organized the team in Chicago in 1898, bought "cardinal red" jerseys for his team to wear.
Super Bowl IX (1974): white jersey Super Bowl X (1975): black jersey Super Bowl XIII (1978): black jersey Super Bowl XIV (1979): black jersey Super Bowl XL (2005): white jersey Super Bowl XLIII (2008): white jersey
The Steelers wore their white uniforms while the Cardinals wore red.
Male cardinals are bright red in color and female cardinals are a reddish brown.
brown