Are all the elements named? e.g. base-center, base-top and so on .

Something like that. Take for instance if I want to edit a file to make changes. I make those changes, and when I reapply the theme, it's like image doesn't exist anymore. Would it be something to do with Inkscape? Like a setting that has t be applied for it to work?

https://develop.kde.org/docs/plasma/theme/theme-details/

Thanks. But I should also say that I've been trying to port png/bmp files to svg. It didn't pan out. Is there a way to do this?

Yes, you need to embed the bitmaps into each element. Linking won't work.

So like data uri embed into the svg file?

It's all in the manual. But why not draw what you want? Why would you need bitmaps?

Because I want to port a theme I really liked on Windows 7. But there are others I really liked. Anyways, I'll look into it more. Thanks.