You can change quick settings theme to true black and the quick settings icons active/inactive status with a color of your choice, (goodlock>theme park >quicksettings) In the end just don’t forget to go into settings>advanced settings>show notification icons (if you don’t do this, the app notifucation icons also get themed and it sucks

Of course you can backup, just get an app like FolderSync installed in there and backup what you want wherever you want.