Coloring is an activity that a lot of people have enjoyed as a hobby during their childhood days. It can invoke the body's so-called "relaxation response." Moreover, recovery from strenuous activities and fatigue can be triggered by this activity. Once the relaxation response has been activated, the nervous system will calm down and relax. This is why many parents resort to giving coloring books to calm their children.However, coloring books have been a favorite not only of little children, but also of working adults.