4 Roles of the Aura
Predictive- ability to pick up problems or opportunities.
Adaptive - Note what affects us and helps us make the needed change.
Responsive - locates and deals with problems, any beliefs, and feelings or sin.
Protective- better care of oneself.

Colors
Red - Life, passion, energy, motivation, linked to providing basic needs for self or others.
Orange - Creativity, feelings, attracted to that which is newly emerging.
Yellow - Intellectual, mental, indicates organizational skills, categorical management skills.
Green - Healing skills, like to see people or projects moving from point A to point B.
Blue - Compassion, understanding, communicable, likes learning and understanding.
Purple - Deeply intuitive, humanly spiritual, color of transformation.
White - Relates to principles, concepts, and purpose.
Silver - Transmission of data from one point to another.
Gold - Universal love
Pink - Human love. Combines white of spirit/purpose with red which protects/provides, life.

Further Information on Auras from books I have read and notes I have taken..
The human aura is an invisible energy filed that permeates the body. It is a field of electromagnetic produced by special energy centers the chakras. This field is not stationary and produces swirls about the body, over the head and below the feet. Auras are multicolored and come in many sizes and shapes. Because we can only see some visible light with our eyes, it takes practice with our minds to perceive the aura. The aura will first appear as a hazy outline around the hands and fingers. You can see lines of energy jump from one finger to another and as the mind is trained you will be able to se more of the aura's many colors and depth. The aura body is comprised of many planes which vibrate at a high and low frequency. The higher frequency is connected to our spiritual needs and the lower frequency is connected to our material needs. Many psychics can see the esoteric body as the auras on the outside and the chakras on the inside. Vibrations and frequencies can also determine peoples moods which can be felt when you come in contact with them. If you notice you can pick up their mood, if they are having a good day, you can feel their vibration, and you feel up, when it is a bad day and negative, you can feel your frequency or vibration be drained by them, which then in turn transfers to you, and you then can pick of their feeling of negativity even in short contact.

Other Aura Color Meanings
Dull Yellow - Selfish
Pale Yellow - Intelligent
Emerald Green - Deceit
Blue Green - Compassionate
Dark Blue - Religious
Light Blue - Higher Spiritual Ideals
Lilac Blue - Highly Spiritual
Pink - Universal love
Violet - Psychic development
Purple - Spiritual Devotion
White - Purity
Black - Hate and Malice
Deep Red - Anger
Scarlet - Irritability
Fiery Red - Sensuality
Crimson - Selfish love
Gray Brown - Selfish love
Red Brown - Avarice
Green Brown - Jealousy
Gray - Depressed
Dull Gray - Fear
Rose - Love