How to Start Paper App with a Black Canvas (or Any Other Colors)

Paper app by WeTransfer is a popular drawing/ sketching app among designers, developers, and illustrators. It is useful for brainstorming, mind-mapping, or prototyping. It is also featured as one of the best note-taking apps in one of our posts.
However, I noticed that it doesn’t allow you to start with a blank canvas, or at least not directly. It didn’t take me long to figure out a workaround for this.
So, here’s how to start sketching in the Paper app with a black background