Wrong contrast inhibits user from determining light colors on external TFT

Hi,

  • Debian 13 stable with:
  • KDE Plasma Version: 6.3.6
  • KDE Frameworks Version: 6.13.0
  • Qt Version: 6.8.2
  • X11
  • HW:
    • Lenovo X13 2-in-1 Gen 4 with Intel Graphics (integrated)
    • external TFTs: 2× MSI PRO MP273UDE, 27" 4K

(It would be peachy if the user would be able to easily copy&paste information within the Settings → “About this System” dialog window :wink: )

The biggest pain point of my current KDE setup is that I can’t see light background colors in our business Confluence in my KDE. This is really annoying and renders my desktop almost useless because we’re using background colors intensively.

Making screenshots with Spectacle is of no use since the effect is either not visible on the result or not present when doing a screenshot. So I can only attach some photos to demonstrate my issue.

On my laptop screen, Gamma looks normal and I can determine light colors:

The issue is only visible on my 2 external TFTs attached via HDMI to “AV Access iDock P10” (KVM switch) which is connected via Thunderbolt to the X11 laptop.

As you can see, the background colors are not visible at all. Left TFT:

Middle TFT:

Laptop TFT (in reality, it looks better than on the photo):

Gama comparison is worse on the external TFTs. The first two fields are basically the same:

Same on the second external TFT:

While playing around with the settings, I noticed something that might or might not have something to do with the issue: focus change in combination with the “dim windows” feature causes some weird behavior:

My goal is to see the background colors on external TFTs at least in the windows that has the focus if not in every window.

Maybe somebody has ideas how to achieve that?

(Please don’t recommend switching to Wayland: Since Plasma Wayland crashes on resume or attaching/detaching the TB-cable of my KVM switch, I unfortunately need to run KDE with Plasma X11 which has lots of annoyances and bugs in contrast to Plasma Wayland. Maybe I’ll invest an afternoon in searching the bug DB to find out which of those bugs are already logged.)

The issue doesn’t only prevent me from seeing light background colors: many UI interfaces do use light contrast elements to draw input lines which I can’t see at all. So this has really an impact on the user experience if many UI elements can’t be seen at all.

Today I was trying to identify any KDE feature that might be the reason:

  • tested but it isn’t the culprit
    • Colors & Themes
      • Theme: switching from “Debian Breeze” to “Breeze”
      • Colors: “Breeze Light” → “Breeze Classic”
      • Plasma Style: “Breeze Dark” → “Breeze”
    • Window Management
      • Desktop Effects:
        • Appearance
          • Background Contrast
          • Blur
          • Desaturate Unresponsive Applications
        • Focus
          • Dim Inactive
            • IMPORTANT: when disabled, the contrast is broken in all windows and not just in the window that has the focus!
              • So actually, I’m looking for a “Dim Active Window” feature as well :slight_smile:

Furthermore, I can confirm the issue with a second computer: a desktop running Debian 13 as well with following hardware: (Sorry, I’m not allowed to post URLs here) with same docking station and external TFTs.

  • Window Management → Desktop Effects → “Defaults”: contrast is broken
    in all windows and not just in the window that has the focus (again)
    until I re-enable “Dim Inactive” which restores contrast in all
    non-focus windows again.

Oh, and the same issue persists when switching to KDE Wayland.