SUMMARY Neon just updated to Plasma 6.0.0. Under Panel Settings, I set Opacity to "Translucent", but my panel remains black and is not translucent whatsoever. I am using the Breeze Dark theme. STEPS TO REPRODUCE 1. Apply updates in Neon. 2. Reboot. 3. Right click on panel and select "Enter Edit Mode". 4. Under "Opacity", select "Translucent". OBSERVED RESULT Panel stays black and is not translucent. EXPECTED RESULT Panel will be translucent. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE neon 6.0 KDE Plasma Version: 6.0.0 KDE Frameworks Version: 6.0.0 Qt Version: 6.6.2 ADDITIONAL INFORMATION I was using the "Panel Transparency Button" widget. That stopped working after the latest Neon update. So, I removed that widget. I then tried setting the Opacity to Translucent, but it does not seem to be working.
That widget probably monkeyed with your panel, and now that it's not working anymore due to not being compatible with Plasma 6, the changes it made are stuck. Does the issue reproduce in a brand new panel, or in a new fresh user account?
I added a new panel at it is a little translucent. Not as black as my original panel, more of a very dark gray. A little better, though. Is there a way to make it much more translucent (completely transparent would be my preference)?
I'm afraid not. It sounds like my diagnosis was correct, so I think it's time to either recreate the panel and use the default appearance styling, or else wait until the widget you were using to change the appearance is ported to Plasma 6. I hear there's also another that does this called "Panel Colorizer" that may suffice.
Thank you!