A Whole Blue World: And All the Stars by Andrea K. Host

This is one of those books that makes you want to cheer! The author, Andrea Host (two little dots over the o), has created a complete reality that you can believe in and a cast that are funny, smart and brave. Madeline Cost wakes up and finds herself in a collapsed train station covered in dust and debris. What can have happened? She had been on her way to meet her famous cousin Tyler, an actor, to paint his portrait in hopes of winning a major art prize... and now, this. She manages to extricate herself from the rubble and finds herself standing on... a body. She makes her way to a dim light source and sees night and stars, but not above, a huge wall of swirling stars stands before her. She reaches out and touches it...and, it knocks her back down into the dust and ruin.
Once she recovers enough, she answers a call from her mother who had been trying to reach her. She tells her to stay inside. There's been a cloud, a dust cloud, maybe germ warfare, and to avoid exposure. It's a little too late for that, but she lies to her mother and says she's safe, so her mother doesn't drive into danger on her behalf. She's on her own.
For now, anyway. Once She makes it to Tyler's apartment, her original destination, she discovers that the world has been invaded...by giant spires that spew the dust clouds and have appeared in major cities across the globe, not just Sydney, Australia. People who had been exposed to the dust find themselves changing color, hints of blue or green. Madeleine strips off her clothes and examines herself... there are no traces of color, instead, areas of her body are a deep midnight blue with stars swirling below the skin.
I don't want to give away all the pleasures of meeting the other characters for yourself. I will just say that they are people you will love, and root for and cheer on and that there is suspense and there are plot twists where you , if you are anything like the Recommender, will be yelling "NO!" and "What!" and "OMG" at your book or e-book. This book is a true and utter delight and one that you want to re-read and one that you, too, will be militantly recommending!