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.
Red Orange Yellow Green Blue Indigo Violet. Red is listed first and starts with your backside. Orange is the groin. When the heart is orange this is supposed to mean two or three things depending on age and gender. For a female it may mean that she wishes for a child or worries about dysfunction or there is a great deal of love in the activity of human junction.