On Vision and Colors are, however, nonessential properties that differ according to the type of light-refracting substance that is used. The top of the upper image is violet. Below the violet is blue. The bottom of the lower image is orange. Above the orange is yellow. In this way, along with the white disk and the black background, four prismatic colors appear: violet, blue, yellow, and orange. This is in disagreement with Newton's claim that there are seven prismatic colors. As the upper image overlaps black, it is seen as violet. Where it overlaps white, it is seen as blue. As the lower image
White As sunlight enters the ice, more light of the red spectrum is absorbed, so the light scattered will be bluish. Clouds are white for the same reason as ice. They are composed of water droplets or ice crystals mixed with air, very little light that strikes them is absorbed, and most of the light is scattered, appearing to the eye as white. Shadows of other clouds above can make clouds look gray, and some clouds have their own shadow on the bottom of the cloud. Many mountains with winter or year-round snow cover are named accordingly: Mauna Kea means "white