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.
1 North flowing = red. 2  East flowing = yellow. 3  South flowing = blue. 4  West flowing = green. 5  On the US map mark segments of rivers with the color that corresponds to the general direction of flow. North flowing = red. 2  East flowing = yellow. 3  South flowing = blue. 4  West flowing = green. 5  On the US map mark segments of rivers with the color that corresponds to the general direction of flow.