There are many factors that you must consider when selecting the light such as intensity, power rate, wavelength, color…; in which the Correlated Color Temperature (CCT) is one of the most essential aspects.
So, what is CCT and why is it important? Please read our information below carefully to find out the answer.
What is CCT? (Correlated Color Temperature)

Correlated Color Temperature (CCT) is a concept derived from Planck’s Radiation Law. As the Law stated, if an object is heated to a certain temperature, it will glow and emit the continuous spectrum. The color of the continuous spectrum depends on the temperature of the object; so when observing the spectrum of an object, we can estimate the temperature of the beam. The unit of measurement of CCT is Kelvin (K).
In an easy-to-understand way, CCT is a quantity that describes the appearance of light, indicates what color emits from the light source, and whether it is warm or cold. The range of CCT is from 1000 to 20000 Kelvin degrees, however, in normal life, CCT of light sources is frequently between 2200 to 6500 Kelvin degrees.
The light sources whose CCT are in the range of 2200 – 3000 Kelvin have warm colors such as red, orange, and yellow, while the more than 4000 Kelvin light sources have cool colors such as cool white, blue.
***Watch the video to see Color Correlated Temperature Explained in detailed
CCT of some light sources

CCT |
Light sources |
1000 Kelvin |
candlelight, oil lamp |
2000 Kelvin |
dawn light, wolfram light |
2500 Kelvin |
incandescent bulbs |
3000 Kelvin |
light in the photo lab |
4000 Kelvin |
fluorescent bulbs |
5000 Kelvin |
daylight, electronic flash |
5500 Kelvin |
sunshine when the sun is overhead |
6000 Kelvin |
sunshine in cloudless weather conditions |
7000 Kelvin |
sunshine in cloudy weather conditions |
8000 Kelvin |
the light in cloudy weather conditions (more clouds than the above) |
9000 Kelvin |
shade on a clear day |
10,000 Kelvin |
cloudy and rainy weather conditions |
11,000 Kelvin |
blue sky without sun |
20,000 Kelvin |
late afternoon on a clear day |
***Read more: Best Natural Light Desk Lamp: Top 8 Best Choices For Office
The application of CCT

#1. Warm colors (2700 – 3100 Kelvin)
Fire is the first artificial light that was discovered millions of years ago. From there on, Human beings adapt to use the fire for light, for cooking, and for heating. As a result, people nowadays are so deeply embedded in our brains the image that fire can make us warm and cozy. Along with the development of technology, the original fire has been replaced by fireplaces, candles, incandescent light bulbs, and LED light bulbs, all of which create a warm color (2700 – 3100 Kelvin).
Warm colors are the perfect choice to comfort people similar to home; for that reason, they are a favorite selection when used for residential space or the place which requires to convey the comfort of home. Almost all hotels and restaurants employ warm colors to make the customers feel comfortable and cozy like at home.
In addition, the warm colors accentuate wood and brick, as well as brighten the red, yellow, and orange objects. However, please remember that the warm colors may not be appropriate for business environments because the cozy and warm working conditions can decrease the working spirit and productivity.

#2. Cool colors (5000 – 6500 Kelvin)
Cool colors are also referred to as “daylight” since the shades of blue in the spectrum whose CCT is 5000 Kelvin create the blue color of a clear and cloudless sky. As a result, cool colors such as green or blue take advantage of their characteristics to make people feel free in outside environments. Specifically, daylight whose CCT is more than 5000 Kelvin provides D3 vitamin for people’s skin and makes us feel happier.
Cool colors are commonly found in working offices, in which the cool lights are regularly used to liven up and lift spirits, especially if the offices do not have sunlight. Besides, both small and large retailers prefer cool colors to warm ones because they provide energy to purchase goods for customers.
***Read more: 6500K Light: Top 7 Best Lighting Choices For Your Spaces
#3. Neutral colors (3900 – 4200 Kelvin)

The neutral color is a new definition that only appears in the mid-1900s along with the development of lighting technology. In fact, neutral colors can not be created from natural lighting sources like warm colors or cool colors.
However, neutral colors have their own advantages. They help to reflect the true colors of objects into people’s eyes. Therefore, the neutral colors are perfect for displaying merchandise and exhibiting artworks (such as photos, paintings…). Therefore, neutral colors are frequently used in photo galleries, art galleries, museums… or used for the tasks that need to see the color precisely.
In addition, neutral colors are employed in multiple-color spaces because the warm colors (red, yellow, orange) or cool colors (blue, green) can reduce or eliminate the performance of other colors. For that reason, almost all companies utilize neutral colors to emphasize the colors in their logos.
Some tips for choosing CCT by application
Application |
Recommended CCT |
Outdoor parking space |
The common CCT range is 3000 – 5000 Kelvin. However, the 3000 – 4000 Kelvin is preferred. |
Common retail |
It is suggested that the CCT of megamall, supermarkets, and stores should be according to the color of the brand’s logo, times, location, and atmosphere. The CCT needs to be changed during the holiday too. Most US retailers regularly select the range of 2700 – 4000 Kelvin for their stores. The mix CCT is also an interesting choice. |
Jewelry store (diamonds, or silver) |
3500-Kelvin colors should be employed. The 3500 – 4500 Kelvin is preferred. |
Jewelry store (mixed metals) |
A combination of warm color (about 2700 Kelvin) and neutral color (4000 Kelvin) should be employed. |
Luxury restaurants |
Warm colors whose CCT is in the range of 1800 – 2700 Kelvin are suitable for high-end restaurants. |
Self-service restaurants |
Most self-service restaurants use the 2700 – 3500 Kelvin light, which is a little cooler than luxury ones. |
Hotel – Lobbies |
The color of the lobbies of hotels is also based on the color of the brand’s logo, times, location, and atmosphere. Most of the USA’s hotel lobbies use the warm spectrum whose CCT is from 1800 to 3000 Kelvin. |
Hotel – Common areas |
The same as hotel lobbies. Both lobbies, hallways, and common areas should match with each other. |
Hotel – Rooms |
The customers need the space that is cozy and comfortable like at home, therefore the 2700 – 3000 Kelvin range is appropriate |
Office space |
Neutral colors or cool colors whose CCT from 3000 to 4000 Kelvin is suitable for the office, which enhances employees’ working spirit and productivity. |
Hospitals |
Cool colors (3500 – 5000 Kelvin) are ideal for hospitals because they create clean atmospheres and a hard-working environment. |
School – Dining space |
The range of 2700 – 3500 Kelvin is ideal for dining space in school or university. |
School – Classrooms |
The range of 3500 – 5000 Kelvin is appropriated for the classroom to promote the learning spirit of students |
***Read more: Best Daylight Lamp for Office: Top 8 Expert’s Choices of 2022
Frequently Asked Questions
How to choose the color temperature for photography?
The connection of the light and color of people, objects and sceneries plays an important role in creating a beautiful photo. Therefore, the photographers should select the CCT carefully before taking a photo. It is suggested that the color of light should make the audience understand the feeling of the sense, such as the forest in summer needs warm light or the river in winter requires cool light. Besides, the CCT is also based on the interest of the photographer and expresses the personality and style of the photographer.
Does color temperature affect our feelings?
In fact, the light can affect our mood. The bright sunlight provides energy for people while the dim light from sleep lamps makes it easy for people to sleep.
According to the researchers, the CCT of the light affects the people’s circadian rhythm, heart rate and mood. The cool light (blue, green) that is similar to the natural sunlight makes us energetic and enthusiastic. The warm light (red, yellow, orange) is romantic and makes us feel relaxed, comfortable and cozy.
Conclusion
Correlated Color Temperature (CCT) is a vital factor that people have to consider when choosing light for the houses, the businesses, the photos. We hope that our article may give you the basic information about CCT that you can apply in your daily life or working tasks.