But I wanted blue crisps

Go on admit it - how many times have you picked up a green packet of Walkers crisps thinking they were cheese and onion?

Thousands must have ended up with salt and vinegar flavoured snacks by mistake because new research reveals consumers strongly associate the colour of the packaging with the product.

Despite the expression "looks don't matter", when it comes to shifting more cans than the opposition off supermarket shelves the label had better be perfect.

Sixty per cent of men and 40 per cent of women choose a product not for content but for colour and design, according to a survey published today. And shoppers subconsciously link 62 per cent of goods with a particular colour.

Director of the Consumer Analysis Group Jan Walsh said: "The figure that really stood out was that 62 per cent of shoppers buy products because of colour on the packaging. It suggests the colour dictates the quality of the product offered and proves it really does sway our decisions. It is such a cut-throat business that if packaging is not right the product will not sell, so now manufacturers employ psychologists to advise on design."

Green is associated with a "healthy lifestyle", yellow with optimism, red as physically stimulating and "indicates to the shopper to get on with it" and blue makes the product feel fresh.

Research also shows there is a direct correlation between the shape of women's bras and pack design. As bras have become softer and rounder products have followed suit.

Mrs Walsh added: "As shoppers become more sophisticated we are demanding better packaging otherwise we will just reject the goods. A manufacturer going against colour expectations is taking a dangerous risk." Eighty-nine per cent of the population believe cans of cola should be red, while three quarters also think tins of soup should be the same colour.

Seventy-five per cent think cheese and onion crisps should come in green packets and 70 per cent believe mineral water should come in blue bottles. Eighty per cent of shoppers need blue and green on a can of tuna and a fish motif communicates "freshness and natural health" with fish products.

Over half of consumers wouldn't try a new product if they didn't like the colour, with three quarters refusing to try a new brand of soap powder if it had brown packaging.

The labels on wine influence purchase decisions the most, closely followed by those on toiletries.

The survey of 600 consumers carried out for John West Foods, also revealed women especially like the idea that a lot of thought has gone into choosing the right design for groceries.