We live in a time where soccer clubs come out with an unnecessary amount of kits, in the 2021/22 season Napoli alone came out with 13 different jerseys, and that doesn't even include goalkeeper or training/warm-up kits.
In complete contrast of this trend we have São Cristovão, a tiny team from Rio de Janeiro that, besides having Ronaldo play in their youth academy, is famous for being the only team in the world with only 1 uniform, all white.
The tradition began out of lack of necessity, by coincidence none of São Cristovão's early opponents wore white, so there was never a need for a second uniform. This kept going forward until 50, 60, 70 years went by and it became a thing.
The tradition is taken so seriously that the Soccer Federation of the state of Rio, where São Cristovão plays regional tournaments deep down in the Brazilian soccer pyramid, allows São Cristovão by regulation to always have the right to choose it's uniform before its' opponent, doesn't matter if the match is home, away or neutral ground.
The only time São Cristovão played a tournament at a national level was the 2000 Brazilian League, a year where the country was restructuring it's pyramid system and couldn't decided who would participate in the top flight, so 114 clubs took part. Unlike the Rio State Federation, the Brazilian Confederation did not have any special exceptions for São Cristovão regarding its' uniform, however, the club notified all the other 113 teams of their long standing tradition and they all agreed to respect it.
Interestingly enough, São Cristovão does specify a second uniform in the clubs constitution if needed, which states it must be all pink. Even so, to this day, São Cristovão has conserved its tradition for over a century and has only ever played in all white.