By and large, local rivals tend to wear contrasting colours.
In England, there is a red/blue split between Liverpool and Everton, Manchester United and Manchester City, Arsenal and Tottenham Hotspur (kind of), Sheffield United and Sheffield Wednesday, Bristol City and Bristol Rovers, and it’s the same in Munich with Bayern and 1860 – so much so that, when Bayern briefly had blue, they still wore red in the derby.
One exception is in Barcelona, where Barcelona and Espanyol both wear home kits with a lot of blue, but there is still enough differentiation that neither changes when they play. In Italy, the red/blue dichotomy is present with Roma and Lazio, Genoa and Sampdoria and, of course, Milan and Internazionale.
Both sides have first-choice kits that feature black stripes but there is usually enough contrast, aided by Milan’s historic propensity to wear white shorts – below, from left to right, are match-ups from 1908, 1969 and 1990.
However, in the modern era, with the need for manufacturers to do something different every year, the potential for problems has arisen and this came to a head in 2016-17. Milan had black, sleeves shorts and socks, while the sleeves and the torso pattern on the Inter strip meant that the black dominated the shirt.
On November 20, Milan were the home side for the first derby della Madonnina of the season and Inter changed shorts and socks to white – there was no need to change the socks but taste won out over necessity.
The game finished in a 2-2 draw but there were a number of complaints about the kits, with the solid-black backs of Milan’s shirts adding to the confusion. So it was that, for the second meeting of the campaign – another 2-2 draw in April – the ‘visitors’ wore their change kit.
Ordinarily, that wouldn’t have been a huge problem as Milan have a great tradition of all-white kits but all of those have had red and black as accent colours. Unfortunately, their 2016-17 alternative screamed Real Madrid. Perhaps because of a perceived socks-clash or perhaps because they couldn’t not look like themselves in a home derby, Inter opted for black change socks.
Normal service of sorts was resumed in 2017-18 as Milan returned to white shorts and socks.