If you have a dual GPU mac, f.lux v34 will install a “f.lux profile” while it’s running, in order to avoid flashing as OS X switches between video cards. You can see this in System Preferences > Displays > Color. This new profile preserves everything in the system profile except the display table, and it reverts to the normal one when f.lux exits, and during the day.

Disabling the profile behavior on dual-GPU Macs

If you have a dual-GPU Mac and this behavior causes problems (i.e. you don’t want us to touch your profile), you can turn it off like this:

defaults write org.herf.Flux disableProfile 1

And then make sure to delete the “f.lux profile” from your Color settings.

To turn it back on again:

defaults delete org.herf.Flux disableProfile

Turning on the profile code for single-GPU macs

If you are experiencing flashing due to an app other than f.lux, it may in some cases help to enable this new behavior on single-GPU machines too. We’re wondering if flashing while running Parallels may be such a case, but we have not tested this as a fix yet.

To do that:

defaults write org.herf.Flux writeProfile 1

And then to turn things back to the default settings, you should delete the f.lux profile from your Color settings, and do this too:

defaults delete org.herf.Flux writeProfile