It says poison, passion and stop right there. It is the most powerful colour on the planet and it is rife with contradictions. Its universal meanings are heat, blood, danger and emotion.

A red light means that the doctor is in. Red cars are sexual status symbols. Red heads are supposed to be firebrands. The devil wears red and so do scarlet women. Those with heart problems are advised to avoid the colour because it is so stimulating. Red light has been known to accelerate plant growth.

In the past, red dyes were expensive, so red walls and fabrics suggested either luxurious wealth, importance or ill repute. Today careful use can easily suggest an Asian influence. Red's connection with heat is so strong that it can make you feel warmer even when the temperature hasn't changed. Too much brings associations with violent emotions leading to impatience, confusion and irritability. Used with caution it can enrich although it does tend to make small rooms even smaller.

In China, it is a wedding colour denoting luck and happiness. According to Hebrew tradition the name Adam, the first man means both red and alive. Advertisers love red because it's a high energy, high impact color; those attracted to it demand to be noticed.