It's all about function and ratio. If you want a space where people will have a quick meeting, you might use bright and exciting colours - people can only stand them for five minutes to half an hour, and that will influence the way they talk to each other in that space. But a meeting room, where you want to talk in detail, shouldn't be painted red (because unconsciously everyone will want to leave) or so bland that you fall asleep. It's all about finding the appropriate use for the space. It all sounds logical enough, but does anyone in the real world take any notice of this stuff? Well, as it happens, accountancy firm PriceWaterhouseCoopers (PWC) takes colour very seriously. So much so, they have a department devoted to it. Anne Muirhead is the head of the future working environment team at PWC and says that colour is an essential part of figuring out how to create an environment in which people will want to spend time. "We spend a lot of time looking at trends, and how people at school and university now - our future potential employees - might like to work," she says. "We discovered that they didn't want plain white or grey walls - they wanted an environment that affected them psychologically in a positive way." As a result, every time PWC refurbishes or opens a new office, employees attend a series of workshops to help choose colours and to ensure every floor is different. Office manager Gordon McIntosh was involved in choosing colours for PWC's Glasgow office. "Before, the office was rather drab with white walls. Now I have mainly yellows and blues - but it's nice to go to another floor and find a completely different atmosphere," he says. "It's definitely made a difference to my work." Muirhead, whose office has also been redesigned, agrees. "The introduction of colour, and that people were given a choice, has made ameasurable difference," she says. "They have a sense of ownership and take care of the space better. But it also affects your mood - when I look up, I am staring at something designed to be calming, imitate natural light, or to help me feel more upbeat." Most companies reckon colour should be about branding. "It's not bad to use brand colours in the office," Kai Stania says, "it depends on the ratios in which you use it. If your colour is orange, then use it in your hall, or lounge but don't use it in office spaces because people will become distracted."