K is very close to true white on most monitors and is the popular selection. Know as Cold White it gives the screen a light blue tinge on older monitors. 6500K , less popular, gives everything a slight reddish tinge and is therefore known as Warm White. You may prefer 6500K for games on an older monitor. Moire refers to some types of distortion that may occur with improperly shielded monitors.
Moire patterns are wave lines or fuzziness and are created by misalignment of the cathode ray.
The Degaussing option enables this during power-on.