These days you don't even necessarily need a separate app like F.Lux or Redshift; Windows and Android have similar color-shifting features built-in to the OS. (Not sure about Mac or iOS.)
There are also other night mode apps that offer other tones. I've been using Blue Light Filter on Android lately and appreciate the level of controls it offers (color temperature, intensity, and screen dim)
It's not a matter of choice of colour, the way f.lux removes the blue is different than just adding an overlay (like Twilight and such do), that's why it needs root.
iOS does but is very subtle about the change. f.lux default settings are quite dramatic and turn the screen very red. Something in between seems right to me.
One day the weather app will get the outside colour temperature locally and match the OS to it. :)
Does anyone know of any way you can keep Night Shift on at all times on iOS or MacOS? It seems when I turn on Night Shift, it automatically turns off next morning when it's daylight time.
I think the same things applies to f.lux on MacOS. I would like for it to be at 1200K at all times but I guess that's not doable and it grinds my ears a bit because you can't do so.