When I was young, differently flavoured crisps came in distinctly different coloured bags; plain crisps were red, cheese and onion were green and salt and vinegar were blue. Generally these colour codes are still used today – at least in the UK. However, one manufacturer (Walkers) is breaking these long-standing rules.
Research at the University of Oxford was recently reported that concludes that the colour of the bag can affect the taste of the crisps inside because of our expectations. It turns out that crisp manufacturers are putting pressure on Walkers to sort their act out and conform to the old rules.
ps. For readers in the USA, we are talking about potato chips.