Why is there a "shadow" around my areola?

I have an olive skin tone and there's a "shadow" around the top part of my areola. It kinda has the look of a bruise but not really. I know it's not a bruise so I'm calling it a shadow. I heard people say pregnancy but I know I'm not pregnant. Is this normal? What causes it? And, how can I get rid of it?

No doctor answers yet