What is the difference between 66 140cbi and 66 144cbi?

66 140cbi is 5000K, and 66 144cbi is 5500K k. Both represent color temperature.

Color temperature (colo(u)r temperature) is a measure of light color of light source, and the unit is K (Kelvin). Color temperature has important applications in photography, video recording, publishing and other fields. The color temperature of the light source is determined by comparing the color of the light source with the theoretical hot blackbody radiator. The Kelvin temperature when the hot blackbody radiator matches the color of the light source is the color temperature of that light source, which is directly related to Planck's law of blackbody radiation.

Color temperature is the most commonly used index to indicate the spectral quality of light source. Generally expressed by Tc. Color temperature is defined by absolute black body. When the radiation of an absolute blackbody is exactly the same as that of a light source in the visible region, the temperature of the blackbody is called the color temperature of the light source. Low color temperature light source is characterized by relatively more red radiation in energy distribution, which is usually called "warm light"; After the color temperature rises, the proportion of blue radiation in the energy distribution increases, which is usually called "cold light". The color temperature of some common light sources is: standard candle light is 1930K (Kelvin-day); Tungsten lamp 2760-2900K；; The fluorescent lamp is 3000 k; Flash 3800 k; The sunshine at noon is 5600 k; Electronic flash 6000 k; The blue sky is 12000- 18000K.