[bdrool]

It happens when you play full-screen videos on a mac. The full screen mode displays in a more direct screen access manner (but only after any overlays, like video controls, have faded out). In this mode, f.lux's color profile changes can cause weird blooming issues, especially in bright ares of the video (like a blue sky). Apple seems to have built their solution in a way that avoids this issue.

It's likely f.lux cannot ever do anything about it. Until Night Shift was available, I've been in the habit of of creating "low color temp" color profiles and manually setting my display to them when it gets late in the day (a crude approximation of f.lux, but ultimately the same thing they are doing). It always produced the same artifact.

Incidentally, I find it strange that f.lux is claiming they output so much less blue light than Apple's Night Shift, since as far as I can tell, all they do is shift the color profile, just like Night Shift does. Anyone who has seen the video issues I'm describing above can attest that there is still plenty of blue light coming out of the screen with f.lux (and manual color profile adjustments). All three accomplish the same thing, it's just that Apple's implementation appears to be cleaner and work in more cases (not surprising -- it's their system, so presumably they know how to integrate with it better than anyone). I think perhaps at most they have a point that the default settings are maybe not "warm" enough, but that's the only flaw I can see.