Reading in Kelvin
Most LED light bulbs will include a Kelvin or K rating which indicates the color temperature. Color temperatures over 5,000K are called cool colors (bluish white), while lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red). Some enjoy the bright white lighting as others may enjoy more yellowish lighting. There is also the blue hue that is more natural compared to daylight.
The color temperature has important applications of lighting, working, reading, displaying, etc. The color temperature light source is measured of an ideal black-body radiator or pure black that radiates light of comparable hue to that of a light source. Color temperature is typically stated in units of absolute temperature or Kelvin with the symbol K.
Sometimes by mistake, cool and warm fluorescent tubes were mixed and notably different color shade of white and yellow. The chart below gives a better understanding of the different color temperatures. For information on brightness, vist the watts to lumens table.

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