The NFL does uniforms - or kits as we know them in the UK - rather differently from other major sports.
In fact, we are now seeing many European football clubs bringing in fourth and fifth shirts, with specific outfits for specific competitions.
But the NFL is much more strict when it comes to the threads being worn on any given Sunday.
Here’s what you need to know.
How do NFL uniforms work?
In general, one team must wear a colour and the other team white.
The NFL allows teams to wear alternate uniforms - a design aside from the home and white uniforms - three times per season, and they can also wear another alternative up to twice.
Teams also wear throwback jerseys on rare occasions, and it is always the home team’s choice whether they wear colour or white.
The visiting team must wear the opposite.
Teams can only have one helmet per season, though they can be painted and decorated with stickers. This is because there is a break-in period with helmets and safety advisers believe it is safer to avoid those periods as much as possible.
In conjunction with manufacturers Nike, who make every team’s uniforms, the NFL used to hold a colour rush week.
This was where all teams wore an alternative uniform which was all one colour.
This scheme was stopped in 2018, but many teams still use colour rush uniforms as part of their alternative uniforms.
Typically,jerseys and pants - as they are known in the US - are a different colour.
This year’s changes
Most NFL teams stick with their jersey designs for a number of years, but we do see changes infrequently.
The big change this year is the Washington Commanders, who have a whole new set of uniforms following their re-branding.
At the moment, all of the other teams appear to be keeping their existing uniforms, but there is already talk of the Detroit Lions and the Arizona Cardinals changing things up in the coming years.
And don’t be surprised if we get some new alternate uniform releases ahead of the new season.