Now that we've covered the basic principals behind the way light works, we need to get pretty in depth about how the color of light is measured.

This can be somewhat confusing, because color is gauged by temperature. Its important to understand the difference between these temperatures, as each will produce a different hue of light. One must also take into account the type of bulb being purchased, as the method by which light is produced varies. When purchasing light bulbs a shopper will notice that the color of the light is measured Kelvins. A Kelvin is a unit of temperature that is usually used in science, or to measure objects which reach extreme temperatures. Kelvins can be translated easily into degrees Celsius by subtracting 273. To convert degrees Celsius into degrees Fahrenheit, consult a different website. Light color is measured this way, because its a consistent way of gauging the amount of heat necessary to produce a given hue of light. The example most often given is heating steel. As the steel is heated it will begin to glow. With each temperature range the metal will glow a different color. First it becomes orange, then yellow, and then finally will glow bright white. Each of these colors is the measured by the temperature of the metal when the color was being emitted. Although this seems like an overly complex and very roundabout method of measuring light, its actually extremely consistent. In technical terms, the heating of metal in such will produce very similar results across a wide range of materials. Incandescent lights produce light by the direct heating of a metal filament. In the case of home lighting, the heat source is electric current. Even though this produces the desired effect of light, its an extremely energy inefficient method of producing light. The new standard of home lighting, fluorescent lights, produce visible light in a rather roundabout manner. Essentially, a fluorescent light converts Ultra Violet light to visible light through the use of coating on the light itself. Color temperature is useful knowledge when purchasing this type of lighting, as the materials in the coating will emit light at specific temperatures. Therefore, a consumer has to know what color temperature their looking for in order to purchase the right light. In order to simplify the selection of lighting for consumers, the lights are arranged into temperature levels. Each successive level is hotter than the one below and therefore emits a whiter light. The lowest level of color temperature tops out at 3500K. Bulbs in this range have orange to yellowish hue. This is because light produced in the wavelength to produce this light makes use of longer wavelengths, and tend to emit more red light. The middle range of color temperature is between 3500K to 4000K. These lights are the middle of the light spectrum, occupying the space between brighter white lights and more mellow yellow-organe lights. This temperature range is the most recommended for use in most rooms. The highest temperature range is above 4000K. This produces bright white lights, and tend to make colors in the room it illuminates rather bright. Light in this temperature range is also useful in counter acting Seasonal Effective Disorder, as it provides the closest equivalent to natural light.