Some authors contend that we have fairly constant auras colors (See Pamela Oslie's book and Barbara Bowers book). These are different from the fluctuating aura colors some psychics see. They are fairly consistent and reflect different personality types. There are about twelve different "Life Colors" according to each author that we can have for a particular reincarnation.
Ive read and believe that each of us function from 3 chakras and therefore three colors effecting our auric field. I am not really sure if this has anything to do with personality, persay' though because character and personality can be effected by the influences around us. It isn't all inbred, in my opinion.
Different strokes for different folks, Obee-wanna-know-be. As in, we each function from different chakras to help fulfill our calling or the reason we incarnated.