All,
In Plasma 5 I created my own SDDM theme (including a nice background), also created a splash screen (using the same background). After I login I get use the same background as wallpaper. A consistent experience in my opinion.
However If i logout I get an ugly black screen holdig my icon, name and options (log off, switcht etc). Is there a way that I can modify this “logout” screen in such a way that it used the same background as in the SDDM them (and splashscreen and wallpaper).