how to change notification transparency?
The transparency of the notifications is determined by the Plasma theme. You can install a theme that has transparency effects though these often can not be changed without modifying the theme source files (I’m guessing it is possible for a theme to offer a configuration option to set the desired opacity - though I’ve never seen something like this).
The other option may have been to set up a window rule to target notifications, but the only ways to identify a notification window are:
- Matching the layer it is on - which is the notification layer - but window rules do not let you match the layer, just change the layer.
- Matching the window type - which is
NET::notification- and that is not a window type that the windows rule matcher lets you choose.
So in summary - you can’t set the notification transparency without creating/modifying a Plasma theme, though one may consider the missing “Notification” window type in the window rules configuration to be a bug - so you might want to open a ticket about it in bugs.kde.org.
The last possible option is to just manually modify the transparency of a shown notification by hovering over it with a mouse and holding META while you scroll up or down - but this only affects the current notification and will not be saved, so I’m pretty sure this isn’t what you want…