Look through OIO Loop and point it above or below OIO Bulb, moving it until you see a rainbow of colors across the lens. In Day Mode, you should see a continuous band of colors, with the bright blue section being the waveolength that promotes wakefullness. In Evening Mode, there should be a clear gap where blue was when in Day Mode. That open space between the green and violet confirms the absense of blue light – which, just like nature – sends the signal to your biology that it’s time to wind down and prepare for sleep. The presense of blue signals Day Mode, the absense of blue signals Night Mode.