It’s the same subtle energy. The easiest way to “see” an aura is intuitively in a situational context.
For example, if a person is talking about something that is important to them, or if they are consumed with an emotion, you can tell there’s an energy around them and you might be able to see it.
Regarding color, some people think that it works like the colors of the rainbow. If all parts of the self are centered, you’ll see a pure white light. If otherwise, a given wheel is more active or charged, that will be the predominant color at that time. So it can definitely change.
A simple exercise to begin seeing the subtle energy with eyes open:
- Ground and center yourself in a dim lit room.
- Lift a hand or finger against a white background.
- Look or stare past it until you see a glow around your fingers.
- With time and practice, you will be able to recognize colors and layers.
Keep in mind that you’re not trying to see with your physical eyes but with a different, more intuitive, kind of perception. This comes with a lot of work and can take a long time to master. Keep working on Focus, Meditation & other exercises.