Fans of 50 Shades of Grey will be horrified to learn that bed bugs are drawn to the colours red and black, making Christian Grey's red room a magnet for the biting insects.Although bed bugs are colour-blind, it was thought they were drawn to darker shades because they resembled blood, which the insects drink. But now scientists believe they are drawn to colours that are most like themselves, as bed bugs like to congregate together. Dark colours also offer camouflage from ants and spiders.Researchers at the University of Florida and Union College in Lincoln made small tents from coloured card and gave bed bugs 10 minutes to choose their preferred covering. The results showed that they strongly preferred red and black, while avoiding colours like green and yellow.The study gives new meaning to Grey's "Red Room of Pain"."We originally thought the bed bugs might prefer red because blood is red and that's what they feed on," said co-author Dr Corraine McNeill. "However, the main reason we think they preferred red colours is because bed bugs appear red, so they go to these harbourages because they want to be with other bed bugs, as they are known to exist in aggregations."The authors suggest that a possible explanation for why bed bugs avoid yellow and green is because those resemble brightly lit areas. These findings are important because they may have implications for controlling the pests.Bed bugs like to huddle together, which is why they may be attracted to dark colours.The colour research could be used to improve traps, the scientists believe, although they haven't ruled out switching the colour of sheets to help prevent infestations."I always joke with people, 'Make sure you get yellow sheets'," said McNeill. "But, to be very honest, I think that would be stretching the results a little too much."I think using colours to monitor and prevent bed bugs would have to be specifically applied to some sort of trap, and it would have to be used with another strategy for control."I don't know how far I would go to say don't get a red suitcase or red sheets, but the research hasn't been done yet, so we can't really rule that out completely."The study was thought up by accident during a conversation between McNeill and her adviser Phil Koehler."We were trying to think of a new avenue to control bed bugs," said McNeill. "My adviser at the time, Dr Phil Koehler, said to me, 'You know, I don't think we have any recent studies regarding bed bug vision or how they respond to colours if they're looking for a harbourage."The research was published in the Journal of Medical Entomology...