@Arnaud I think you may have encountered a feature that is not ours, but usually from Intel or Windows. You'll want to google "disable Intel DPST" or, if you have Windows 11, you can find an advanced option about changing brightness based on content, and turn it off.

@katjustice28 thank you - can you post f.lux options > driver info so we can understand which devices & versions are involved?

@cowboyzed right now it is applied for all the displays equally. We have a per-monitor disable on Windows, which we will look at adding to macOS too.

@thedoctor2031 yes it is definitely showing here "gamma ramp works=0" for one of the two, which indicates a problem with the video driver. Does it behave differently if you relaunch f.lux?

Edit: it looks like Mac was hiding icon overflow on my top bar on smaller screens. When I connected my computer to an external monitor with a bigger screen, the icon appeared! There may be a way to fix this on the mac side (closing programs in the top bar that aren't flux should be a good start for users who don't have access to a bigger screen), but just wanted to share in case this is helpful to people!

@sezchwarn check out https://justgetflux.com/news/pages/macquickstart/

There should be an icon in the menubar

@adityapstar

Ok so I know this post is over a year and a half old, but I thought I'd share what resolved this for me for any newcomers facing this issue.

All I did was change which monitor was classed as the main monitor in the windows settings.

Settings ---> Display ---> Multiple displays ---> Tick "Make this main display" on the monitor not currently set as this ---> Re-tick your actual main monitor.

This is what resolved it for me, on a windows 11 machine without giving f.lux admin control as it's a work PC. I was also running this via a daisy chained 3 monitor set up connected to the laptop via a single USB-C cable.

My Driver Info below incase anyone needs that for reference:

Intel Corporation 31.0.101.5333: Intel(R) Iris(R) Xe Graphics (20240221)

Dell P2425HE(DisplayPort), 527 x 296mm, built 2024
Chromaticities:
R=0.665039 0.324219
G=0.311523 0.628906
B=0.142578 0.061523
W=0.313477 0.329102
sRGB gamut: 100%, AdobeRGB gamut: 70%

Generic PnP Monitor, 293 x 165mm, built 2019
Chromaticities:
R=0.644531 0.338867
G=0.324219 0.613281
B=0.155273 0.048828
W=0.313477 0.329102
sRGB gamut: 85%, AdobeRGB gamut: 60%

Dell P2425HE(USB Type_C), 527 x 296mm, built 2024
Chromaticities:
R=0.665039 0.324219
G=0.311523 0.628906
B=0.142578 0.061523
W=0.313477 0.329102
sRGB gamut: 100%, AdobeRGB gamut: 70%

Dell P2425HE(DisplayPort), 527 x 296mm, built 2024
Chromaticities:
R=0.665039 0.324219
G=0.311523 0.628906
B=0.142578 0.061523
W=0.313477 0.329102
sRGB gamut: 100%, AdobeRGB gamut: 70%

Unlimited gamma ramp=1, Internal ramp=1
Monitor 1 on Intel(R) Iris(R) Xe Graphics
Has VCGT profile=0, Gamma Ramp works=1
Monitor 2 on Intel(R) Iris(R) Xe Graphics
Has VCGT profile=0, Gamma Ramp works=1
Monitor 3 on Intel(R) Iris(R) Xe Graphics
Has VCGT profile=0, Gamma Ramp works=1

Windows Build: 22631.3880

Hi,
Thank you for sharing this it is really interesting.

@herf i cant send screenshot but in win10 i can change intensity, if you right click on the night mode panel and go to settings, there will be a setting for the night light parameter right under the switch on and switch on night mode button.

@Jokester2101 You have the "hotkeys" checkbox off, so it should not affect the Windows key.

The only place we register a hotkey is related to this, and if f.lux is relaunched it does not even call the windows code to ask for the hotkey. It's specifically registering Windows+End.

@hehee we will look into it - this means that f.lux saw two different states in the hub, and to avoid a "race condition" where we fight another app, we are waiting for it to be stable before making changes. But as you say it would be annoying if it is always doing that.

Hi!

This is exactly what I am looking for too. Making everything monochrome red is great. But why does it inverts everything at the same time? That should be a separate thing. All my icons look odd, all shadows are wrong, photos are useless, faces cannot be recognised, basically everything looks bad. So instinctively I've tried to use MacOS built in inversion feature to "fix" it, but unfortunately macOS inverts the image after it is tinted red by f.lux, so in inversion mode it becomes cyan. (My brain froze when I switched. I didn't expect the amount of blue light into my face.)

I'd assume it could be very hard or almost impossible to make f.lux filters come after OS level filters, so it'll never play nicely with macOS built in inversion feature I think.

But that should not mean that the red filter should only be available with inverted luminance. Can we gat a mode / option to use red filter without flipping dark and light parts of the screen please?