It seems there's a fight going on between gray, black, and blue to win the "least appetizing" food color award. Have you noticed how there are few naturally occurring foods that are gray, black or blue? Go figure! Blue is definitely a strong contestant because it never feels appealing to eat. It's associated with calmness, and people who love blue would enjoy sleeping more than eating. Even a blue light in your kitchen, dining room, or restaurant will greatly suppress your appetite. Go for it only when you're trying to lose weight and are actively trying to eat less.