Created attachment 131149 [details] Example I would be very happy if the Breeze theme for KWin offered an option for transparency, allowing Windows Aero style blur for the background. It's one of the main missing features for the default theme, due to which I've been using my own Aurorae based theme (Freeze) just to work around this limitation. When you go to System Settings - Appearance - Application Style - Window Decorations - Theme, click the little icon with the pen over Breeze (Edit Breeze Theme), there should be a slider to allow adjusting the transparency. At the default value of 0 the behavior remains unchanged... when above 0, the background of the decoration should become transparent and use the blur effect behind it. I attached a screenshot from my modified Freeze theme as a close example of how this should look like (50% transparency).
This is in fact why we have 3rd-party theme support--so we don't need to cram every conceivable option into the default theme. :) I don't think we'll be adding blur support into the Breeze window decoration theme sorry. :)
Unless bug 395725 gets resolved, it doesn't make much sense to add blur support to Breeze. We would just get more duplicate reports about the issue.
This was rejected rather quickly. I noticed vanilla KDE added a lot of customization options recently, thus I figured such a simple feature wouldn't be a problem... especially with Windows Aero remaining such an influential model in desktop themes. Konsole for example added support for a transparent / blurred background in recent years. Hopefully someone can attempt this in a fork of the Breeze theme which would also help, the old Oxygen theme had one called Oxygen Transparent in the days of KDE4.
Are you talking about a transparent decoration or transparent window contents? The aim of the Oxygen Transparent fork was for the window contents.
(In reply to Christoph Feck from comment #4) > Are you talking about a transparent decoration or transparent window > contents? The aim of the Oxygen Transparent fork was for the window contents. Titlebar and border background, excluding the text and buttons which remain at full opacity. See the attached screenshot which shows how I worked around this and achieved the desired result using an Aurorae theme based on Breeze (this method has limitations so I suggested it as a default feature for Breeze).
Even better would be for the Colours KCM to allow RGBA values to be specified, rather than just RGB, thus allowing transparency to be fed to any theme.