Yes, in many cases, you can. It depends on the platform or software you're using to create or view the story.
Yes, you can. However, the ability to change the background color varies. For example, in some advanced publishing tools, you have extensive color choices and can even set gradients. But on basic note-taking apps, it might just be a few preset colors or none at all.
Sure. Usually, if you're using a dedicated story writing app or website, there'll be options to customize the background color. Some might offer a limited palette, while others give more flexibility. But for simple text documents, it might not be possible directly.