Rival

Corinthians biggest rival is called Palmeiras - the pigs.
Palmeiras is currently playing in the second division in Brazil - it has been downgraded twice in the past 10 years.

Palmeiras color is green, therefore, Corinthians fans do not tolerate anything green in the stadium of a Corinthians game --> this includes t-shirts and jerseys from other random teams. A green t-shirt in the stadium and the person wearing it will be kindly requested to take it off. Better do it when the request is kind, because in denial the request may be a little tough.

So, if heading to a Corinthians game, please avoid green colors.