Have you ever thought the color of the wall you stare at every day looks different later in the day than when you first wake up? If you think the reason for that is lighting, it could be but if you are seeing green instead of gray, researchers from the University of Houston in Texas explain that it is because your color perception changes and gets fixed by rest.

On June 9, Bhavin Sheth, assistant professor of electrical and computer engineering at the University of Houston will present his team's findings at SLEEP 2010, the 24th annual meeting of the Associated Professional Sleep Societies LLC, in Texas.

Sheth explained, "our findings suggest that wakefulness causes color classification to drift away from neutrality, and sleep restores color classification to neutral" and this study is the first to analyze the role of sleep on how we see/perceive the world.

The very small study of five participants  showed that the color gray would be defined as gray after an average of 7.7 hours of sleep but during hours of being awake the same gray would be described as having a greenish tint.

The authors noted, "sleep restores perception to achromatic ‘equilibrium'," and the use of "overnight full-field monocular stimulation of a flickering red ganzfeld failed to nullify the recalibrating sleep-induced effect."  Adding that there are not any external stimuli that can provide the same benefits as sleep in respect to the way individuals see color and perhaps other facets of life.

Sheth and his team caution that their conclusion is tentative and more research is needed.

In the meantime, seeing the world a bit clearer in full-color is another reason to get plenty of rest nightly, not to mention it boosts memory, learning, motor skills and much more.

Study abstract, "Effect of sleep on the perception of color": http://www.journalsleep.org/ViewAbstractSupplement.aspx