Is there a way to add new styles to page style?

Not yet possible. But if the module works like the switchtheme module, it can be true.

I think more styles are only possible and practicable for the form template.

Then, MySQL queries are required to store the data.

1. style name, example: "White/Black" (translation problem?)
2. text color, example: "#ffffff"
3. background color, example: "#000000"
4. font weight, example: "bold"
5. status: active or not, example:"1"

Update: Translation problem of the "style name"...

"Mobile" or "print styles" is a theming issue.