Color Temperature - Unit of measure-Kelvin (K). The color temperature of a light source in comparison with a "black body radiator" and plotted on a "Planckian Curve". The higher the color temperature, the greater the blue component in the spectrum and the smaller the red component. Daylight bulbs have a color temperature of 6000 K where a warm light would have a color temperature of 2700 K.

Cool White - Reference to the color tone or appearance of light produced by a lamp for a specific color temperature. Cool White is the least expensive and most widely used fluorescent lamp color in lighting today. Its name comes from the cool, airy atmosphere it creates wherever it is used. Modern, efficient and business-like, it is popular in stores, classrooms, offices, corridors and factories.

Warm White - Reference to the color tone or appearance of light produced by a lamp for a specific color temperature. The color of the light from this lamp makes a factory, office or store seem warmer and friendlier. Together with the "white" lamp, this is the most efficient of all fluorescent colors. It is a good choice to blend with incandescent bulbs.

Color Rendering - Lamps may have the same color temperature but different rendering properties due to the spectral composition of their light. Certain colors of the spectrum are transmitted and appear to the human eye to be brighter than others; e.g., yellow appears much brighter than red to most of us.