It's very noisy. In the sense of there being a lot of pixels that would make up either colors. Your eyes and brain try to make sense of the noise and "decide" what color it is. The strongest correlation that seems to exist is the time people get up in the morning. Early risers seem to see white more often, night owls have a tendency for blue. It might be caused by the amount of daylight vs. artificial light that people see throughout their waking hours.