Choosing the Right Color: 1  Light color is measured on a temperature scale referred to as Kelvin (K). 2  Lower Kelvin numbers mean the light appears more yellow; higher Kelvin numbers mean the light is whiter or bluer. 3  Most ENERGY STAR certified bulbs are made to match the color of incandescent bulbs at 2200-3000K. For a whiter light, look for bulbs marked 3500-4100K. For bluer white light, look for bulbs marked 5000-6500K.
Visible Light. Visible Light Waves Visible light waves are the only electromagnetic waves we can see. We see these waves as the colors of the rainbow. Each color has a different wavelength. Red has the longest wavelength and violet has the shortest wavelength. When all the waves are seen together, they make white light.
The spectral colors of the rainbow are caused by dispersive refraction. Newton established that refraction causes the dispersion of light into its constituent hues. He named seven colors, in symmetry with the seven distinct notes in the Western musical scale.t is the ratio of the speed of light in a vacuum (c) to the speed of light in this medium (v): n = c / v. The bending of a light as it crosses the boundary into a different medium is determined by its refractive index, or how much the light is slowed down in the new medium.