I read somewhere that RED being the colour of fire and blood is particularly associated with energy, war, danger, strength, power, determination as well as passion, desire and love. Red is a very emotionally intense colour. It enhances human metabolism, increases respiration rate, and raises blood pressure. It has very high visibility, which is why stop signs, stoplights and fire equipment are usually painted red. In advertising, red is often used to evoke erotic feelings.
Personally, I happen to think colours are more schitzophenic than that, changing meaning according to the situations we face.