Right now, we use a plain blue background for both SDDM and KScreenLocker, which generates complaints from users that it's ugly and doesn't match their wallpaper. We had a big discussion in the VDG telegram room and arrived at the following conclusions:
- SDDM and KScreenLocker should both default to using the current default KDE Plasma wallpaper
- If the user changes this default wallpaper to anything else, SDDM and KScreenLocker should do nothing
In essence, we are simply moving from a plain blue background to the current Plasma wallpaper. One really cool effect is that when Plasma is updated, the SDDM and KScreenLocker backgrounds should change to match it! This is a big branding win.