Am I seeing an aura or the opposite color?

Q:When you see someones aura how do you know for sure that it's their own aura and not just the color that the clothing radiates? Like can you perfectly tell because the aura is huge and spread out?

Eva's Response: Good question. The first place I will see a person's aura is above their head. This is because I'm usually looking them in the eyes and talking to them when I see their aura. I see shapes and colors and all sorts of fun stuff.

Now to your question about whether it's color from a person's clothes. Every color has an opposite color - this wikipedia article goes into detail. So for example, a person wearing a purple shirt would radiate yellow.

There is a quick way to tell the difference: close your eyes. If you can still see the color, it's a trick of the eye and you are seeing the opposite color. If you can't, it's likely you are seeing an aura.