Proxmox + Chromium based brower => Scrambled colors

Hi,

I am experiencing an issue under the following configuraiton:

When I run this configuration, my colors are scrambled/inverted, and instead of the shadow around the window, a black box is displayed.

The issue does NOT happen with any non-chromium based browser; Firefox is fine.

What I tested:

  • First I tried installing a new VM on the production host with Manjaro Plasma, but the issue persisted.
  • Next I tried installing directly (bare iron) on another computer with a totally different hardware configuration. The issue could not be observed.
  • Then I installed Proxmox on the other computer and created a VM (1CPU/4Cores/8GB Ram, rest default) in proxmox → The issue reappeared.
  • Finally, I installed Manjaro XFCE on both my production proxmox and the other computer, and the issue did not appear. (This really surprised me)

I have also posted this in the Proxmox forum (sorry, it’s german, but it’s basically the same), but as this seems to be happening only in this specific software configuration, I believe we need to tackle it from both ends at the same time.

At the very beginning, I also tried some software configuration options that I found in other posts, but it didn’t help. I posted about that on reddit with no response.

Testing procedure:

  1. Boot into Manjaro live ISO.
  2. Open a terminal
  • pamac install chromium
  • <enter>
  • y
  • chromium

Im guessing this has to do with either

  • X11 vs Wayland (firefox now will automatically use either backend … whereas chromium will just be using X11 [or xwayland] without making any config).
  • Something something ~Hardware Acceleration~ or similar.**

** Technically neither should be hw-accel by default … but firefox will at least try its best, while chromium will be flatly software-only unless you combine a specific conjouring of flags at just the right time when the stars align, and only with certain hardware.

But its just a guess. Could be some blink bug for all I really know. :slight_smile:

I had similar thoughts, that is why I tried chromium’s GPU parameters (details in my reddit post).

But why doesn’t it happen on Manjaro/XFCE?!
Unless I miss something, it looks to me that both of them run the same Xorg:

image|689x434

image|689x434

I have just verified something:
I have installed Manjaro/Plasma on in a VM, then installed XFWM via pamac.

After this I logged in using different sessions:

  • KDE / Xorg → Problem with the colors
  • KDE / Wayland → Problem with the colors
  • XFWM / Xorg → All working fine.

I believe this proves that this problem only happens with KDE, and that it does not depend with the use of Wayland or Xorg.

Just a thought - with KDE kwin is the window manager whether you use x11 or wayland.

The binaries are kwin_wayland and kwin_x11

I have compared the versions of the software components involved in the various distros I had tested. I noticed that only Manjaro/Plasma ran KDE version 6.

ChatGPT told me that Kubuntu 24.10 also uses KDE version 6.

I have been able to reproduce this issue also with Kubuntu 24.10.
→ At this point, it seems to be a problem with the combination of Proxmox and KDE version 6.

Maybe take care to check, as the subsequent releases have seen pretty significant changes.

  • 6.0.* - This was the Stable Branch and ISO version until recently
  • 6.1.* - This is the current Stable branch version
  • 6.2.* - This is the current version in Unstable Branch

Both of them are on the same version: 6.1.5 → Stable.
(FYI: Kubuntu 24.10 is a stable release as well…)

I have just switched to Manjaro/Plasma unstable; it is on verison 6.2.0 and the issue still happens there.