I just installed Ubuntu (version 18.04.03). I noticed that blue is being rendered as purple. Further that this only happens on some applications. In GIMP (image editor) the color rgb(0,0,255) renders as the expected blue. However in the following apps, the same image appears purple:
- Chrome
- Firefox
- Image Viewer
- Probably other apps, haven't tested all
In these applications, the image renders correctly:
- GIMP
- File Browser
- Sublime Text
- Probably other apps, haven't tested all
In this previous question, the culprit was "Night Light" mode. However on my computer this is off. Enabling it turns the screen distinctly orange-ish.
The fact that blue renders correctly on GIMP (an image editor where color fidelity is important), leads me to believe it has something to do with a setting similar to Night Light mode...
How can I turn off whatever "feature" is causing this color change?
Update:
Here are some photos. It is hard to capture with a camera, but the Image Viewer (left) renders the blue test image distinctly purple, whereas GIMP (right) does not.
Also interesting is that the GIMP render remains the same shade of blue regardless of the viewing angle. Whereas the Image Viewer's shade of purple changes with the viewing angle. Looking down at the screen from the top, it is a distinct purple. Whereas looking up at the screen from the bottom, the purple almost looks like the blue it is supposed to be.
The moire pattern observed in the Image Viewer is not visible to the eye. However, maybe it is related to the color change depending on viewing angle effect...
Top view:
Bottom view:
Turning off color management seems to have resolved the issue. The setting can be found at:
Settings → Devices → Device Colour Profiles
A restart is required to see the changes.
On Ubuntu 20.04 head to Color in Settings and turn it off. Worked for me.