So while not doing what I should be I was cooling myself off with this tiny fan with a hand-crank. For some odd reason I decided to point it at my monitor and make it go in reverse and noticed that at a certain speed the blades of the fan appeared to be blue and yellow and rotating in the opposite direction of the actual rotation of the fan. What causes this to occur? I assume it has something to do with the refresh rate of my monitor but I'm clueless as to why this happens. Thanks in advance!