I think the OP meant to suggest that we can control our auras. I believe that we can.
People who are mean and evil have a black aura. While people who are nicer tend to have white or more colorful auras.
We just need to focus on the good and create positive energies around us. I think learning about zen has really made my aura lighter and brighter. I have no idea what color it is though. I only have a vague understanding of auras.