It can make a person passive and easily led or taken advantage of. An overdose of blue can make you feel cold, sad and depressed. The colour indigo is associated with the mysterious and the profound. People attracted to this colour usually look beyond the surface of things. They are drawn to higher things, sometimes even the occult.
Indigo stimulates the intellect.
It gives a person a sense of courage, authority and inner calmness. At the physical level, indigo purifies the blood. It is useful in treating diseases of the ear, nose and eyes and for sinus problems. It is also used for curing varicose veins, diseases of the nervous system, boils and ulcers, and skin disorders. An excess of indigo can give you a headache and make you feel sleepy.