Isn't it funny that every time you pass a McDonald's or see the sign you instantly become hungry for two all beef patties, special sauce, lettuce, cheese, pickles, and onions on a sesame seed bun? It's actually not, and it has to do with the colors of the golden arches.
The McDonald's logo is yellow and red for a reason. See, the color red is associated with being active and it jumpstarts your heart rate. Yellow is associated with happiness and is the easiest color to see in daylight.
Your brain processes color before processing words or shapes, and that's why McDonald's chose those colors. Red and yellow combined makes you hungry and encourages you to stop in and eat, while making you feel happy.
Color philosophies are being used more now with McDonald's to influence and change the way people think about the fast food giant.