There’s been a subtle change to popular chocolate bars in the UK

Chocolate brands have made some subtle changes you might not have noticed (Picture: Bloomberg via Getty Images) Cadbury chocolate has been wrapped in a rich, shiny shade of purple since 1914. The specific shade, Pantone 2685C, is as instantly recognisable as the vibrant turquoise colour that features on tins of Heinz Baked Beans. But neither colour was selected randomly, according to Professor Charles Spence, an experimental psychologist from the University of Oxford. The expert tells Metro these iconic hues are actually a clever trick to ‘make the products look better’. The shade of blue on the tin is iconic (Picture: In Pictures via Getty Images) ‘Heinz is one of the best examples of packaging colour contrast – the baked beans look much more golden against the turquoise on the tin. ‘It optimises the product, and makes the beans look better,’ he explains. ‘And it’s the same for Cadbury, the brown chocolate looks more vibrant against the purple brand colour.’ These brands got in early with their colour choices and have been really successful with them – and it’s why you’ll see others try to use similar colours. Cadbury has become so protective of its packaging that the brand has previously tried to stop competitors from using Pantone 2685C on their packaging and even fought to trademark the shade. Ask Metro Use AI to go deeper into the stories you care about – powered by Metro and trusted publications. But it’s not just the colour of the packaging that makes the product more appealing – the shape of food can also have a major subliminal impact on the way you think about it and the way it tastes. The purple shade makes the chocolate pop (Picture: LEON NEAL/AFP/Getty Images) ‘I’ve done a lot of work showing that people associate round shapes with sweetness, and angular shapes with bitterness,’ Charles says. ‘We’ve found that people associate round chocolate with sweeter milk chocolate, and angular shapes with dark chocolate, as it’s more bitter, with a higher cacao content.’ Because of this association, Charles claims a brand could change its chocolate recipe and cut the sugar content, but so long as they change the shape of the bar, making it rounder, consumers will perceive that it’s just as sweet as it always was. ‘Some of that sweetness is coming from the shape, not the sucrose.’ Why our brains associate flavour and shape is ‘a bit of a mystery’, according to the expert, but a likely explanation could be that we view round shapes as ‘safe’. ‘Round things are not threatening, whereas angular shapes could be seen as threatening and dangerous,’ he shares. ‘This even applies to something like pizza, if a slice of pizza is pointing towards you on a pizza box, you won’t like it as much as if it’s pointing away from you.’ Since sharing his work on shape and taste in 2012, the expert notes that Mondelēz went on to change the shape of Cadbury’s Dairy Milk chocolate bars, making the edges rounder. Following this change, fans of Cadbury began writing into newspapers to complain that the beloved chocolate didn’t taste the same, and had become ‘sweeter and creamier’. Charles adds: ‘They hadn’t changed the recipe, but by rounding off the pieces to reduce the weight a little bit, exactly what we predicted would happen, happened. ‘Making it rounder made the chocolate taste sweeter, but because sugar is so cheap, they didn’t bother reducing the sugar content in the product, and so it went wrong, in a way.’ And it’s not just Dairy Milk bars where changes to shape have been made. In recent years, Nestlé has made some big changes to Quality Street sweets, with The Purple One and the Orange Crunch, both becoming more circular. And it’s happening all the time, according to Charles. So you might want to keep a close eye on your favourite sweet treats. ‘You’ll see a lot of confectionery companies rounding off chocolates, so they can reduce some of the ingredients, but they’ll never talk about sweetness, because that’s not a conversation they want to have with the consumer. ‘But if you know what’s going on behind the scenes, you can look out for the shape and think about it.’ This article was first published on June 4, 2026. Do you have a story you’d like to share? Get in touch by emailing MetroLifestyleTeam@metro.co.uk Deals of the Day Kurt Geiger's new Notting Hill collection is a love letter to London's chaotic weather I’ve found the Hoover gadget that could make cleaning your floors so much easier I tried L'Oréal Paris's new PDRN serum and my skin looked glossier after one use This new Cricut gadget turns your favourite photos into stickers in minutes From kitchen hatches to burgundy walls – the biggest home trends for 2027 Arrow MORE: All the deals and freebies to save cash for Christmas and beyond — from M&S to Boots Arrow MORE: Greggs fans say it’s ‘criminal’ this treat is only sold in London Arrow MORE: Pot Noodle flavour urgently recalled with ‘do not consume’ warning issued The Slice Your free newsletter guide to the best London has on offer, from drinks deals to restaurant reviews.