Auracle by Gina Rosati

Anna Rogan has a secret which she has only shared with her best friend, Rei. Anna can astrally project out of her body. She can go to different places in the world and universe. She can also see people's aura. "My physical eyes are like sunglasses, filtering out the colors, but when I'm out here, the aura that emanates from every living thing is clearly visible to me. People, animals, and even plants are surrounded by this transparent bubble of color. Over the years, I've learned that the colors can tell you quite a bit about a person. Like right now, Rei is surrounded by this lemonade yellow, which looks nice,but it's the same shade of yellow my mom has when she's sold a house to someone and the loan falls through. Sigh." (Auracle by Gina Rosati) 

While her spirit is traveling different places, she witnesses the death of a girl from her school, and she sees one of her friends standing there. Her innocent friend is falsely accused for murder. 

When Anna goes back to where she left her body, she realizes she can't find it. The spirit of Taylor Gleason (the girl from Anna's school who was killed) took Anna's body. Anna is unable to go back into her body. She has to get back into her own body before Taylor ruins her life or someone else's.

 Once she understands that she cannot do this alone, she turns to her best friend, Rei, for help. "To me, faith is about trusting my instinct when logic tells me I'm an idiot." (Auracle by Gina           Rosati) Even though Rei told her not to astrally project, because he thought she might not come back, she did. She had to face the consequences, which were not being able to get back into her own body. 

Eventually, Rei and Anna find a way to get her classmate, Taylor, out of her body.