Take a look at this pic, is it possible to configure openbox to have this sort of blurred effect?
You need to use compositor for that. Like compton or compiz with emerald. There is original reddit post
You need to use compositor for that
What is a compositor exactly?
Compositor application which render your window. It's composite extension for X. You can read about different compositors on arch wiki
cuddly_bear Oh so it basically I install a compositor with OpenBox then.
cuddly_bear Is it possible to do the same thing on KDE plasma as well?
joe213 yes. KDE has build in functionality for that. It's theme dependent.
MrSatan What do I do to get this theme exactly?