What is color temperature?

With the appearance of LED lighting technology, solutions with different color temperatures have become widely available also among end-user products.


But what do we exactly mean by color temperature in lighting technology?

Color temperature is a characteristic feature of light that refers to the color of light, more precisely its white shade. As white color is made up of different colors, there might be visible differences between two colors of white as well. In the case of a traditional lamp, the light comes from the glow of the filament, therefore in that case the color temperature is the same as the temperature of the filament. This is where the symbol K for Kelvin comes from. In the case of fluorescent lamps and LED lighting solutions there is no such a physical connection, thus in these cases we talk about Correlated Color Temperature (CCT) instead.


What does Kelvin stand for?

Kelvin is the base unit of temperature in the International System of Units (SI): 0 Kelvin stands for absolute zero (-273.15 °C), while 273.15 K is the equivalent of 0 °C, thus we can convert the traditional °C into Kelvin by adding 273.15 to it. For example: 100 °C = 100 + 273.15 = 373.15 K

With an increase in color temperature the red components of the light decrease, while the blue components increase; therefore, the higher the light’s color temperature, the “bluer” it is, and the lower the color temperature, the “yellower” its color will be.


Examples of color temperatures:

  • Candle: 1900 K
  • At dawn or at sunset: 2500 K
  • Household incandescent light bulb: 2800 K
  • Low sun position in the morning, afternoon: 4800 K
  • Average sunlight: 5600 K
  • Sunny weather in the shade: 6000 K
  • Daytime, cloudy sky: 8000+ K


Areas of use:

Typically the following color temperature ranges are used in the case of lighting technology solutions:

Warm white color temperatures below 3400 K, typically between 2400 K and 3000 K.
Slightly yellowish lighting color, can be best compared to the light of sunrise and sunset, therefore it maintains wakefulness to a less extent but it also affects thermal comfort  - this is why it is also called warm light. It is an ideal choice for use at home, especially in bedrooms and the living room.

Neutral white between 3400 K and 5000 K.
There are no other added tones besides white, thus accurate color rendering may be achieved with this lighting and as such it is suitable for lighting almost every room. An ideal choice for lighting work spaces and offices.

Cool white color temperature over 5000 K, typically between 6000 K and 6500 K.
Besides the white color there is also a minimal bluish tone present, therefore this lighting provides an elegant, icy effect thus stronger brightness and clearer lighting can be achieved. Excellent for lighting public spaces, offices, work spaces, hospitals.

We use four different color temperature ranges for Avide lighting technology solutions:

  • extra warm white (EW, extra-warm) products under a color temperature of 2700 K
  • warm white (WW, warmwhite) produces with a color temperature between 2700K and 3300K
  • neutral white (NW, neutral white) products with a color temperature of 4000 K
  • cool white (CW, cool white) products with a color temperature over 6000 K