As many of you may know, or not, it has been proven by science that all that surrounds us, everything is made of energy. Taking this into consideration we advance into another concept radiation, a by product of energy.
Taking these 2 things we can put them together and try and understand a phenomena that is understood in parapsychology(more into it) and in various spiritual practices as an aura.
Auras are a very subtle and invisible to the naked eye slight radiation that surrounds one's body. In a non religious way, it is general belief that everything has an aura and its quite understandable since all is made of energy, something more than others.
A very curious thing that many believe in concerning auras is that their color, or the colors of its various layers show various things about the person, such as mood, feelings and thoughts thus creating a group of people that dedicate themselves to aura reading techniques.
It is said that every color of the aura representes an exact emotional state and its very easy to accurately tell one's mood or feelings by aura reading.
Auras are depicted as well in various religions, Buddhism per example depicts the various colors of ones aura in their flag as well as the colors of the chakras(more on it). In western mysticism, like the Kabala, the aura is a sort of outer contor of the astral body(more here) within.