Default background color of SVG root element

Question

I\'d like to set a default background color for the entire SVG document, to red for example.

Answer 1

Let me report a very simple solution I found, that is not written in previous answers. I also wanted to set background in an SVG, but I also want that this works in a standalone SVG file.

Well, this solution is really simple, in fact SVG supports style tags, so you can do something like