Wallpaper-curtain shows an image with low-opacity on top of other windows and desktop.
If you're sad not to see any wallpaper due to too many windows. You can display a translucent image above everything.
This can also be used in your crontab to stop you from remote working outside
of office hours, see below.
wallpaper-curtain --opacity 0.25 /my/wallpaper.jpg
Since wallpaper-curtain has no window, it can't be closed easily. Click the icon in system tray to quit it.
Else, kill the process with Ctrl-C or pkill:
pkill -f wallpaper-curtain
Display a red curtain over every window when outside office hours
# generate the red curtain
convert -size 4000x4000 xc:red ~/redbox.png
# add this to `crontab -e`
0 7 * * 1-5 pkill -f wallpaper-curtain
0 19 * * 1-5 DISPLAY=:0 wallpaper-curtain -o 0.7 ~/redbox.png
This does not prevent using the session, it's a more kind of warning. Hardlocking accounts can be done with /etc/security/time.conf
Requires Python3 and PyQt6, and a compositing window manager for translucency to work.