Brazilian club Flamengo’s nickname is the Rubro-Negro (‘Red-Black’) and the club traditionally uses their hooped home kit with white shorts and hooped socks.
Sometimes, black shorts have been worn when clashes have arisen, however historically it wasn’t the case that alternative socks were used. The reason for that isn’t an aversion to looking like AC Milan, but rather because white shorts and socks are associated with Rio rivals Fluminense.
In 2014, that bridge was crossed, though. Flamengo visited Santa Catarina side Criciúma at the Heriberto Hülse Stadium for the eleventh round of the Brazilian League. The hosts wore a yellow, black and white shirt with black shorts and socks, meaning that Flamengo turned out looking like this, using their white away socks.
The uncommon kit combination was lucky as Flamengo won 2-0. Presumably the positive result in the mashup becoming more popular. Two years later, in 2016, Flamengo faced other Santa Catarina club, Figueirense league. Flamengo used the 2015 away socks because the 2016 away kit wasn’t released yet and they lost 1-0. A year later, Flamengo went to Salvador to play against Bahia and, despite the home side having red socks, the white shorts/socks combo was used again as Flamengo won 1-0.
The most recent instance came in the 2019 Copa Libertadores, away to Ecuadorian side Emelec in the last 16. Flamengo lost the first leg 2-0 but in the second leg, wearing the traditional hooped socks, reversed the disadvantage, winning 2-0 in the normal time and won in the penalties 4-2.
This qualified them for the quarter-finals for the first time in nine years and they went on to win the competition for the second time in their history.