Electrical Tip of the Day: Florescent lamp color is rated in degrees Kelvin. Natural sun light on a clear day is about 6000K. Florescent lamps are available in a wide range. From as low as 2000K (which tends to be the old yellowish cool white color) to as high as 7500K (which tends to go into the blue / red spectrum). If you are not happy with the light quality at your office or place of business chances are a lamp change out can make a huge difference.