@herf I did that and also updated my GPU drivers. Same issue only when using f.lux and rebooting. Perhaps it only affects certain hardware. I have a Surface Laptop Studio 2. Are there any logs I can provide you?

I have made a pretty big jump from Windows 7 to Windows 11 in last few months. On Windows 11 I am experiencing the same thing and it's killing my eyes. In my case, f.lux gets disabled once the system receives a notification which usually comes from Outlook in my case (new mail). After few seconds, the colors are back to yellow automatically, but this quick moment is enough to receive a deadly dose of the blue light in the evening, I have never experienced it working on Windows Vista & 7 for 15+ years.

@Burgerkrieg I think I figured it out, at least in my case. Checking "Always use Windows internal color table" fixed it for the misbehaving monitor, which was otherwise doing exactly what yours was.

@herf Yes, they support HDR. To be specific they are both an Acer Nitro 27".

Additionally, I am using Windows 11's Auto HDR setting. Which, to my understanding, changes a display to SDR if the content (or just games? That is all I see it with at least) does not support HDR.

@Chikins the ones we read say "VCGT profile=1" so it is not a full profile in this case.

@tyealia yes the DisplayLink device is forcing them all to use the same settings because the USB adapter has disabled color settings. See if this post helps: https://forum.justgetflux.com/topic/3629/displaylink

@cjmanca can you post f.lux options > driver info?

My machine here doesn't appear to notice this case (even when I unplug the second monitor) so I want to figure out what's going on there.

@macroarray I think it may be based on this sample, which is up near 50,000K: https://fluxometer.com/rainbow/#!id=Outdoors/Blue Sky LA 2PM

This is especially blue but it is common to find the blue sky at 20,000-30,000K. CCT does go up dramatically as things get bluer, it's approximately 1/linear.

Most meters will only say CCT in a particular range (e.g., our measurement software goes to 100,000) - maybe the number is too large for this meter to report...

@herf Awesome appreciate it! 👍

@zero00 we have had better luck with DisplayLink or native (thunderbolt or displayport) connections. I should ask if this monitor has worked in the past for you with dimming controls?

@vsrawat Just use the '/noshow' parameter [source].

@WhiteColorQuestion f.lux does load the system profile to set the "normal" white mode it shows during the day, but it should leave no lasting effect if you uninstall & reboot. Are you aware of any other software that might have reduced the brightness previously?

@herf
Thanks, I see that now but I didn't notice it before you mentioned it.
What does the Disable for a specified program do? Does it set the display to 6500K and is that what the Return to Full Brightness does?

Do all these options do the same thing? Or can the colour temperature be at 1900K when "Return to Full Brightness" is enabled? It's not very clear what the keyboard shortcuts do. I would think that if the colour temperature was set to 1900K then Alt+PgDn would only reduce the brightness from 1900K and go up to 1900K maximum. That would be different to Full Brightness would it not?

@flux_onetimepost I am wondering, whether some old version of f.lux would work in such a manner that we are able to manually specify the screen colour without extra smarts from the software?

@duskdevilza usually this is due to a USB connected monitor (which does not have full color controls). Sometimes these notes can help:

https://forum.justgetflux.com/topic/4653/tinted-screenshots-or-fullscreen-apps-and-games-missing-f-lux