I should also mention that I find with auras, if we look at the aura of someone whom is random, or just kinda crazy, in some way, they don't have one set color that is there all the time.
A good example would be a friend of mine, or even myself. My friend, she is random, her emotions can be strange, like she can be happy, and sad at the same time. I've noticed, and she has mentioned it, that she is always happy, even when sad.
For me, things can be uncertain, I feel that my aura, would be like the aurora borealis, the colors change often, it's all a bit, complicated.
I also should mention, that with dark auras, or certain auras, they can be like tendrils, not waves, lashing out instead of flowing.