Coca-Cola uses a mind-bending optical illusion to sneak into 'blue' football stadiums

Racing Club's Estadio Presidente Perón in Argentina isn't a place to turn up dressed in red. Racing wear blue, while red is the colour of arch enemies Independiente, who are based in the same Buenos Aires suburb of Avellaneda. But Coca-cola has found a cheeky way to sneak its brand colours into the stadium

We've pointed out before the popular Coca-Cola optical illusion that's being going around for years on social media. The images appear to show a familiar red coke can but actually contain only the colours blue and grey. Now the mind-bending illusion has crossed over from TikTok to the terraces.

The marketing agency WPP Open X, alongside VML and Grey, picked up on the Coca-Cola illusion and used it to sneak the brand's colours into stadiums in where red is an anathema – the ads were also displayed at Arena do Grêmio in Brazil.

With support from Ogilvy and WPP Media, the campaign featured large billboards displaying the optical illusion alongside the phrase: "Here are only the colours you love And a Coca-Cola". It also appeared along routes to the stadium, around entrances, in areas where fans gather and in social media extensions.

How does the Coca-Cola illusion work? It seems is our brains get confused by the way the cone and rod receptors in our eyes respond to colour and light. We're susceptible to interpreting grey as red when it's surrounded by blue.

Our familiarity with Coca-Cola's branding may play a role in enhancing the effect, making us even more likely to interpret the can as red because that's the colour we assume it to be.

The advertising campaign confirms our suspicion that the best optical illusions can serve a practical purpose as well as simply being a lot of fun to look at.

It's not the first time that Coca-Cola has shown an awareness of the how its brand colour can polarise. It's previously produced blue cans and banners for Brazil's Parintins Festival on the island of Tupinambarana in the Amazon due to the rivalry between the dance troops Boi Caprichoso and Boi Garantido.

For more illusions, check out photographer Joseph Ford's 'invisible jumpers'.