Most football teams, from the youth teams right on up through the NFL, have at least two different sets of football uniforms. They have the all-white version, featuring white pants and a white jersey, typically worn at games played in other team's stadiums; and they also have sportswear in their own team colors, which the teams typically wear on their home field.
What's interesting about this two color concept of football uniforms is that there is actually no standard rule for when the teams have to wear which uniform, including at the NFL level! Basketball, baseball and hockey players have official "home" and "road" uniforms, so there is never a question as to which team will wear the white uniform and which team will wear the "dark" uniform, but in NFL there are no standard home and road football uniforms! The color of the sportswear is decided by the home team; if the home team decides to wear white, the visiting team must wear their colored football uniforms, and vice versa.
Everyone knows that darker colors attract and retain more heat than white. In the early season games of the NFL, temperatures sometimes reach 100 degrees or more! Many teams are becoming smarter, and going against tradition by choosing to wear their white apparel on the home field, forcing their opponents to wear the darker colored football uniform in an effort to stay cooler and gain the upper hand during the game. But what happens when the visiting team "forgets" to wear the correct uniform? It would be much to confusing to have both teams in white attire, so when the visiting team forgets their darks, it forces the home team to wear their colored football uniforms.
In 2003, the Bronco's came to the Charger's field in the wrong unifrom, and since the Charger's were supposed to have the choice of uniform for the game- the Bronco's were fined $25,000, and the Charger's were allowed to pick their uniform color when the two teams played together on Bronco's field. (Bronco's ended up wearing their white football uniform on their home field- the first time in over a decade).
The entire confusion and possibility of fines could all be avoided if the NFL enacted a general rule of official "home" football uniforms and official "road" football uniforms like MLB, NBA and NHL has. There would never be a question as to which team will wear which uniform, and it couldn't be used as a strategy to try and gain the upper hand by beating the heat, or "forgetting" the correct color uniform in an attempt to upset or confuse the home team.
While a youth football team certainly wouldn't be charged $25,000 for wearing the wrong uniform color to an away game; the same basic tradition follows for schools that have more than one football uniform. The youth sportswear tends to be the "dark" uniform at home, and the "white" uniform when visiting another school's field. If a school only has a single football uniform, it would consist of a colored jersey to match the school's color, and either white or colored pants.