【Wemightthinkweknowwhichcoloursdowhat．TheideathatredwakesusuporbluecalmsusdownisdeeplyrootedinWesternculture．Butdotheyreallychangeourbehaviourinthewaysthatweassume？Whenitcomestoscientificresearch，ther】

　　We might think we know which colours do what．The idea that red wakes us up or blue calms us down is deeply rooted in Western culture．But do they really change our behaviour in the ways that we assume？

　　When it comes to scientific research，the results are mixed and at times contested．Some studies have found that people do better on cognitive tasks when faced with red rather than blue or green； others show the opposite．The idea is that if you repeatedly have a particular experience surrounded by a certain colour，then you eventually begin to associate that colour with the way you were feeling or behaving．A school career spent reading your teacher's red writing circling your mistakes forever makes you link red with danger．Blue meanwhile is more likely to be associated with calmer situations like marvelling at a big blue expanse of sky．

　　Of course there will always be exceptions---the comment from the teacher saying"well done"is also written in red．It is true that people do make different associations with different colours，but whether this translates into behaving in a certain way or succeeding at a particular task is a different question．

　　In 2009researchers tried to clarify the situation．They sat their participants at computer screens coloured blue，red or"neutral"and tested them on various tasks．With a red screen people did better on tasks requiring attention to detail，but when the screen was blue they did better on creative tasks．In practice this might be tricky．In a classroom you might want to think creatively some of the time and pay attention to detail at others．

　　However，when another team tried to repeat the study with a larger group of people in 2014，the effect of colour disappeared．The initial study consisted of just 69people．In this new，bigger study，of 263volunteers，background colour made no difference．

　　So colours might well have an effect，but so far those effects have been difficult to demonstr