The goal of meditation and mindfulness isn’t to become a blank, Zen-like slate. You might get there at times, but only once you are able to sit, nonjudgmentally, with discomfort.
However, every excuse (or very good reason) you find to skip meditation is a sign that you need to meditate ASAP. Stop clinging to the idea that you have to meditate at a certain time of day for a certain amount of time.
The truth is, your aura probably isn’t one uniform color. The aura is said to be comprised of layers, and layers may represent the energy you’ve picked up, as well as different colors indicating your physical, emotional, and mental states.