Kubuntu: No dark theme in 22.04, worked fine with 20.04.

[Fungus]

I've read the other "dark theme" topic, but not found any solution to my problem, so I'm trying my luck..

On Kubuntu 20.04 both the IDE and any app created with Laz was displayed nicely with any dark theme selected in the system. Recently I installed Kubuntu 22.04 and neither the IDE nor any apps created with it will display in a dark theme - everything remains in silverish colors. On both systems I've used the repository version of Laz, currently 2.2.0, and I suspect that it may have something to do with declining support for GTK2.

Could anyone give any suggestions on how to fix this?

EDIT: I found this info from KDE and it seems that GTK2 theming has been removed in KDE > 5.20. I'll try the mentioned solutions and post back what I find..

EDIT2: Copying the dark theme into the light theme folder as suggested in the KDE link works, but it looks surprisingly horrible compared to what was in *buntu 20.04, so I'm giving up on the dark theme.

[Raf20076]

Dark theme is not good for your eyes.

When it comes to visual-acuity tasks and proofreading tasks, studies have shown that people with normal and corrected vision perform better with Light mode. This means that text in Light mode is clearer and quicker to understand for people with normal or corrected vision.

The researchers put this down to the fact that when we look at a bright background, our pupils constrict and increase acuity while scanning text. When looking at a black background, the opposite effect occurs, and dilated pupils make it harder to focus on the text. Dark theme  also causes your eyes to dilate. Since there is less light to take in, your eyes have to work harder to see clearly. Eye dilation can reduce your vision's sharpness, so you may have to strain to see well.

I never use dark theme on anything.

[dbannon]

You may be better building a Qt5 version of the IDE from source ?  That way, you could use the Qt5 tools to control the colours, qt5ct or the ways of mapping Qt5 apps colours to any particular GTK2 theme you choose.

But Raf20076 is right, dark themes are bad for your eyes and just plain ugly IMHO !

Davo