Red is a primary color across all models of color space. It is the color of blood. It is often associated with love, passion, and lust but also danger and aggression. It is frequently used in relation to Valentine’s Day. It can also be used to signify danger or warning but it is also associated with importance. For instance, it is used for stop signs and fire engines. In China, red is often used to symbolize good luck or happiness, and is used for many holidays or weddings. It also represents communism.