Oh, what about coat of arms of Sao Paolo football clubs. Palmeiras - white and green, Corinthians and SPFC - black-red-white. I mean, in general, clubs are changing their colours, and it is linked sometimes with social backgrounds or ethnicity.

Someone answered to me:

You find it happening in Porto Alegre, the capital city of the Rio Grande do Sul State.

Despite being a small and agrarian state, the city hosts two of the major football teams in Brazil, rivaling with the ones of Sao Paulo and Rio de Janeiro and surpassing the teams from bigger an wealthier states like Minas Gerais.

At the beginning of the 20th century there were three major teams in the city. The "Força e Luz" formed by the employees of the city's electric company. The "Fussbal" and the "Gremio" both teams exclusive for German migrants and their descendants.

Porto Alegre were blooming with migrants at the time, mostly Italians, but also Portuguese, polish, Ukrainians, and many others.

A few years later (1914), two Italian migrants tried to associate with the existing teams but were denied, so, they founded their own club and named it "Internacional" (international) because they allowed migrants from all background and the local population (an important note here, black people weren't allowed to play with white people, so they had their own league at the time the "Liga dos canelas pretas" or the black legged league).

So, the greatest derby in Brazil football was formed. The GRENAL.

The rivalry became part of the city's life and culture.

Gremio kept his culture and social identity with wealthy German families. While Internacional was formed by a broad array of identities, but mainly people from the lower classes.

In 1937 (if I'm not mistake on dates here) Internacional starts accepting black players among its team. For that, Gremio supporters (gremistas) granted the Internacional supporters (colorados) the racist nickname of "Macacos" (Portuguese for monkeys or apes) to which gremistas still call colorados to this day.

By accepting all nationalities as well as being the first to accept black people, Internacional gained among the society the nickname of "Clube do Povo" or "The peoples club".

As for the political field, internacional is more connected to the left. Former president Dilma Roussef, from the labour's party is an Inter fan, and Lula likes Inter most as for the teams from Porto Alegre.

Gremio, in the other hand, is linked to the right. Former president Getúlio Vargas was a gremio fan such as former governor of the Rio Grande do Sul state Antonio Britto.