A stimulant, red is the hottest of the warm colours. Studies show that red can have a physical effect, increasing the rate of respiration and raising blood pressure. Use red when you don't want to sink into the background. Use red to suggest speed combined with confidence and perhaps even a dash of danger. A little bit of red goes a long way. Small doses can often be more effective than large amounts of this strong colour. Multiple shades of red and even pink or orange can combine for a cheerful palette.