3200 5600 Klevin (Bulbs)

Color temperature is measured by a unit called the Kelvin (K). The Kelvin thermodynamic temperature scale is defined so that absolute zero is 0 kelvins (K). (Note: The Celsius and Fahrenheit scales are defined so that absolute zero is −273.15 °C or −459.67 °F). Imagine heating a bar of steel and observing the color of the bar at increasing temperatures. At some point the bar will appear to glow a dull red. As heat is added, the dull red turns to yellow, then to white, then to bluish white, finally to blue.