When playing ArmA 3 in full screen it bypasses Windows' default colour calibration settings.
My screen is very 'blue' by default, and playing ArmA with non-realistic colours is a bit of an insult to both its realism and its graphical fidelity (in my eyes it looks like crap unless my colours are accurate). {F17547}
Install a custom colour profile (for example, mine is here: http://www.mediafire.com/?1a5dzowr5ikww3d), open up Windows' "Color Management" tool, check it is associated to your monitor, navigate to "Advanced" tab, for "Device profile" select the name of your custom one. At the bottom of the window, hit "Change system defaults" and repeat the above steps.
Play ArmA 3 alpha, and notice your screen will be pre-calibration. Alt + Tab and cycle back to ArmA 3, not releasing Alt. You will see we are now using the default, and if we release alt to make ArmA 3 the active window again the calibration will cease to be active.
Image below is before/after. Obviously it won't look perfect due to the camera's white balance, your own calibrations (default or not) but it will be representative of the difference.
Closing due to lack of activity in over five months. If this issue is still reproducable for you, please create a new ticket for it or ask for this one to be re-opened.