F.lux keeps switching when the screen gets bright.
It happens most noticeably when i am browsing on pages with white backgrounds, like this forum, or google, i have also noticed it happening in games once or twice.
It goes from blueish to orange and sometimes back again, but it also happens sometimes on the same page when nothing has changed.
It does it on random intervals sometimes every 5-10 seconds, sometimes every minute or two.
I am on Windows 10 and i got an Nvidia card, just say the word if you need more specs.