London - Waitresses who wear red get up to 26 percent extra in tips than they would wearing other colours, researchers have claimed.

However, the sexes tip very differently – with the bigger tips coming only from male customers.

Female diners will give the same kind of amounts for service every time.

Yet men, whether they realise it or not, add anything between 15 and 26 percent more to a waitress in red than they would if it was the same waitress wearing a different colour.

The test was simple. Take 11 waitresses in five restaurants over a six-week period and ask them to wear the same kind of T-shirt every day but alternate the colours.

Previous research has suggested waitresses could earn more if they acted provocatively or wore more make-up than their colleagues.

But this study, by the Journal of Hospitality and Tourism Research, only changed the T-shirt’s colour – every other aspect, from make-up to behaviour, remained the same.

When wearing either black, white, green, blue or yellow T-shirts, the size of the tips from both male and female customers was almost identical.

But when the waitresses wore red, the size of the gratuities went up by between 15 and 26 percent from male customers, yet stayed the same from female ones.

A total of 272 restaurant customers were studied by researchers Nicolas Gueguen and Celine Jacob for the international journal of the tourism industry.

Even as a T-shirt, it showed just how much the colour red was perceived by men to increase the physical and sexual attractiveness of women, said the researchers.

The researchers wrote: “As a colour, red has no negative effect on women customers, and it could be in their interest to wear red clothes at work.”

The team previously found that slapping on red lipstick also improved tips.

They found customers were two-thirds more likely to leave a gratuity to waitresses with luscious red lips.

Providing, that is, those customers were men.

The sociologists from the Université de Bretagne-Sud, France, tracked the tips left for seven waitresses over two months against the variously coloured lipsticks they wore.

In almost 450 transactions, waitresses wearing pink or brown lipstick, or none at all, got tips on average about 30 percent of the time.

But when the waitresses put on red lipstick, male customers tipped half the time – and left more money.

There was no significant change among female customers, however. – Daily Mail