Black font at some App, while using dark theme

[Lukas1818]

At some application the font is black and ignore the theme setting. Even I have sent the color to white.

Anki:

matplotlib:

But in a huge number of programs the font is white.

It looks like the programs ignore the “Colors” section and follow only the “Application Style”.

I have switch manual from cinnamon version to kde by installing the plasma group.

[raguse]

Looks like it’s Kvantum controlled theming. Due to Cinnamon before you will have set an environment variable that uses light theming. Check your /etc/environment, respectively Kvantum.

Are you still using and switching to Cinnamon? If you solely stay on Plasma you might install package plasma5-themes-breath and switch to color scheme Breath / Breath Dark, whichever you prefer.

You can also use Breeze Dark in the meantime and see if it is the same.

[Lukas1818]

Are you still using and switching to Cinnamon?

Hi Cinnamon is still installed, but I did not start it anymore. I have disable the lightdm services.

Check your /etc/environment, respectively Kvantum

❯ cat /etc/environment
#
# This file is parsed by pam_env module
#
# Syntax: simple "KEY=VAL" pairs on separate lines
#

This files comprises of comments only.

You can also use Breeze Dark in the meantime and see if it is the same.

I have already test this, same issue.

A friend of me, with does use sway and plasma-settings, has test Anki, too and have the same issue.
Maybe this is only an issue of Anki or the qt python library?
The Anki light theme is not even a light theme, it does also use the system theme.

[raguse]

If you don’t use Cinnamon anymore you might clean your system of it. With it I think Kvantum is also not needed anymore and that removes also all Kv Themes. I don’t have it installed on Plasma. It’s all up to you how you want to proceed with it.

You can also check the same env in (systemwide vs. user-specific)

cat ~/.profile

Regarding Anki, I just installed it and can confirm the dark font on dark background.
However, change in Anki Menu > Tools > Preferences > Basic > Theme: Dark and it has a dark theme. It runs on Qt6 so the looks is slightly different, well because of Qt6.
For other applications please also check in application preferences whether you have an option to set a different theme.
Anki started in terminal:

anki                                                      ✔  1m 38s  
Running with temporary Qt5 compatibility shims.
Run with DISABLE_QT5_COMPAT=1 to confirm compatibility with Qt6.
Preparing to run...
Qt warning:   OpenType support missing for "Noto Sans", script 15 
Qt info: 

GL Type: desktop
Surface Type: OpenGL
Surface Profile: NoProfile
Surface Version: 3.1
QSG RHI Backend: OpenGL
Using Supported QSG Backend: yes
Using Software Dynamic GL: no
Using Multithreaded OpenGL: yes

Init Parameters:
  *  application-name Anki 
  *  browser-subprocess-path /usr/lib/qt6/QtWebEngineProcess 
  *  disable-features ConsolidatedMovementXY,InstalledApp,BackgroundFetch,WebOTP,WebPayments,WebUSB,PictureInPicture 
  *  disable-setuid-sandbox  
  *  disable-speech-api  
  *  enable-features NetworkServiceInProcess,TracingServiceInProcess 
  *  enable-threaded-compositing  
  *  in-process-gpu  
  *  use-gl desktop 

[Lukas1818]

Thanks for your help.

In the .profile files is the env QT_QPA_PLATFORMTHEME define. Should I care about it?

❯ cat ~/.profile
export QT_QPA_PLATFORMTHEME="qt5ct"
export EDITOR=/usr/bin/nano
export GTK2_RC_FILES="$HOME/.gtkrc-2.0"

Changing the env to kde or unset it, has no effect to Anki.

Running anki-qt6 at the terminal I get the following output:

❯ anki
Preparing to run...
Starting main loop...
Qt debug: Icon theme "gnome" not found.
Qt warning: Wayland does not support QWindow::requestActivate()

[raguse]

Does changing Anki theme in preference work or not?

@Lukas1818

Qt debug: Icon theme "gnome" not found.

That comes from qt5ct, since it’s configured in your .profile.
Unset #export QT_QPA_PLATFORMTHEME=“qt5ct” and try again.
Log out and log on needed I guess!!!

The same here, should you not use Cinnamon anymore qt5ct and also qt6ct is not needed anymore.

With regards to Anki you find a bit more information here Github.

[Lukas1818]

Thanks for your help removing the env does not have any effect to Anki.

You should delete your ~/.cache/bazel folder. Bazel does create a lot of cache files.

[raguse]

Yes it doesn’t affect the look of Anki, only the application preference change does.

And yes, cleaning cache helps often in Plasma.

Have a great weekend!