Correlated Color Temperature refers to the temperature (in Kelvin) of an ideal blackbody radiator (a theoretical object that emits light based on its temperature) that radiates light of a color similar to that of the light source in question.
Since most artificial light sources do not behave like blackbody radiators (especially LEDs and fluorescents), we use the term “correlated” to indicate that it’s an approximate match in perceived color to that of a blackbody.
CCT (Correlated Color Temperature) is a specification of the color appearance of a white light source. It is measured in Kelvin (K) and describes whether a light appears warm (yellowish/red), neutral, or cool (bluish).
As the temperature of a blackbody increases:
At lower temperatures (~1500–3000 K), the light is reddish or warm.
At mid-range temperatures (~3500–4500 K), the light appears neutral white.
At higher temperatures (~5000–6500 K+), the light is bluish or cool.
| CCT (K) | Color Appearance | Example |
|---|---|---|
| 1800K | Very Warm | Candlelight |
| 2700K | Warm White | Incandescent bulb |
| 3000K | Soft White | Halogen lamps |
| 4000K | Cool White | Office lighting |
| 5000K | Daylight | Overcast sky |
| 6500K | Cool Daylight | Noon daylight, camera flash |
| 10,000K+ | Very Cool/Blue | Blue sky |
CCT tells you the color of the light.
CRI tells you how accurately the light renders other colors compared to natural light.
Example: Two lights can both be 5000K, but one might make colors appear more vibrant (higher CRI) than the other.
Mood and Atmosphere:
Warm light (2700K) creates a cozy, relaxing atmosphere.
Cool light (5000K) is energizing and good for task lighting.
Application Suitability:
Homes: 2700K – 3000K (warm and soft).
Offices/Schools: 4000K – 5000K (bright and alert).
Hospitals/Laboratories: 5000K – 6500K (clean and clinical).
Circadian Rhythms:
Cooler, blue-rich light affects melatonin production, so it’s used during the day. Warm light is preferred in the evening to reduce disruption to sleep.
Using a spectrophotometer or colorimeter, the light spectrum is analyzed and plotted on the CIE 1931 color space diagram. The closest point on the Planckian locus (blackbody curve) gives the correlated color temperature.
At Bangladesh Sunlight Technology, we make choosing lights easy. Our carefully designed collections bring you modern, reliable, and timeless lighting solutions.
We deliver premium-quality LED lighting at the best value. From our own innovations to trusted partner products, every option is built for efficiency and durability.
We understand lighting can feel complex. Our expert and friendly support team is always ready to guide you toward the right solution with confidence.
At Bangla BaTi, we go beyond just lighting—we deliver innovation, reliability, and future-ready solutions tailored to your lifestyle, business, and projects.
You cannot copy content of this page