How can I make f.lux darker?
-
What do you mean by "darker"? Redder? You can use Alt+Shift+Page Up and Alt+ Page Down or Alt+Shift+F11 and Alt+Shift+F12 to adjust the the color temperature beyond what the interface lets you do. You can get the color temperature to be 100% red at 800K. If your monitor is still too bright at 800K, then you should turn down your monitor's brightness.
F.lux can also adjust the black level with Alt+Page Up and Alt+Page Down, or Alt+F11 and Alt+F12. While this won't adjust your monitor's backlight brightness, it still helps.
-