Thanks @Paul-Harris - for some context, f.lux v4 avoids constantly looking for color changes and tries only to "fix" what other programs do in a few specific ways, so you're seeing what's expected, except that f.lux should definitely be detecting any new screen that makes your desktop bigger, so that's a bug. That list currently includes: plugging in a new device (which seems like it's not working here), returning from sleep, and switching apps (like alt-tab). When you plugin a device, does it look right for a bit and then reset later? Or does the tint instantly disappear?

Thanks all. Installing the newest Nvidia driver also fixed it for me.

@onotole f.lux actually modifies this setting for activation at sunset. Then I assume it sets the "dark theme" back to unchecked, once sunrise happens. It's probably enabled by default in f.lux, so look in the settings there first.

@oschlag Ah, sorry for making this duplicate thread then! Thanks for the link.

@Mango Thanks, that seems to work. Good to have the bug confirmed too.

The problem seems to be still existent. I am using a OnePlus One with CyanogenMod, Android 6. Only the standard color driver works for me, not Qualcomm or Tegra. After a few seconds it is not black background and red text but red blackground and black text... Please fix it :disappointed:

@raj.seshadri You need to have the app, i.e. Safari, running, and in the foreground, to see the option to enable or disable f.lux for it. For example if you're in the Finder, you won't see the option for Safari. Does that help?