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
Full-spectrum light since marine or coral-reef aquariums often require intensely blue light. Gardening under lights keeps plants blooming almost year-round, for a wintertime harvest. Grow lights are specifically intended to support plant growth, although with varying degrees of success and energy efficiency. Some plants grow better when given more of a certain color light, due to the mechanism of photosynthesis. Specifically more blue wavelengths enhance vegetative growth and development, while the addition of increasing amounts of red light enhances budding, flowering and fruiting. In recent years, full-spectrum lighting has been used in the treatment of seasonal affective disorder (SAD) through the use