When we were little, we were attacked to bright, colourful things. In fact, bright colours are not only for little children - the human eye, no matter what age, is programmed to detect shape, size, distance and movement, as well as colour, in order to collect information about the surrounding - a vital skill for survival. Colour is one form of sensory input that your brain uses to interpret important elements of your surrounding. Dark colour usually mean unsafe, while bright colour, sure as certain fruits, make us feel safer.