Re: F.Lux
No risk of any damage, but just don't do any color correction work while it's on. The result will be spectacularly bad on computers not running F.lux.
Color correction work should always be done with the monitor set to D65 white, preferably also with the use of a good hardware color calibrator.
(Yes, there are other valid white points for specialized situations, but D65 is most common.)