Well, our brains are only wired up to detect a limited spectrum of colors. There are insects and birds that can detect a greater variety of color. So, how can it just exist in our brains?
well, I think that if you are aware (mindfulness) about your thought patterns you can steer them, and usually what you think you become, because your thoughts drive actions.
In my personal experience practicing self awareness has helped with this. I understand that there are factors outside of our control, but what goes on within us can be controlled to some extent with effort and time.