So it's NOT possible. Thanks, would have saved us a lot of scrolling. It just seemed stupid that it wasn't possible to remove the PINK factory wallpaper.
Android: If it's not easy. it's probably impossible.
iOS: If you can't figure it out, we designed it that way.
That was it. Thanks!
Also, On a Galaxy S7, you can also click Settings > Search, and type 'one handed'.
You can do this with any setting, if you know the name. Much easier than scrolling through a bunch of menus looking for the right one.