The color red, which is associated with intense feeling or interaction, symbolizes everything from passion and desire to danger and wrath. In general, the color red is connected to all things physical and emotional, particularly in a primitive sense. The expression to "see red" demonstrates this perfectly.
Red represents both the devil and Valentine's Day. It stands as a color symbol of lust, love, aggression and vigor. Studies have shown that people viewing the color red tend to experience physical effects, such as higher blood pressure, more rapid breathing, increased enthusiasm and confidence and a sudden spike in libido.
Red catches the eye, which is why it came to represent caution, stopping or emergency. It also represents aid as the color of the symbol for the international nonprofit organization, the Red Cross. Many national flags incorporate the color red for its suggestion of courage or boldness. However, the color does not share the same meaning in all countries. For example, in China red is a sign of good luck and prosperity, while in Russia it represents communism. In South Africa, red is the color worn by people who are mourning. The Japanese consider the sun to be red, not yellow.