Like notaries, witnesses aren't generally required in order for a contract to be legally enforceable. However, each state may require special kinds of contracts (e.g., real estate deals, wills, and marriage agreements) to be witnessed by a third party in order to be binding.
McDonald's, apparently, use red and yellow because red=fast and yellow=hunger (hence fast food!). Remember also that meaning is what we create. It does not exist in the color itself and individual meanings may or may not exist in different cultures and individuals.
Color Symbolism. White symbolizes Purity, virginity, innocence and virtue. The color Yellow signifies renewal, hope, light and purity. Color Symbolism: Orange symbolizes courage, endurance and strength representing fire and flame-Green symbolizes nature, fertility, hope and bountifulness. - The color Red is thought to symbolize fire and is associated with power and importance.