Colour Temperature – What is the Kelvin Scale?

Colour Temperature – What is the Kelvin Scale?

Jul 12, 2021, 18:00:00

Color temperature, is defined as “the temperature of an ideal black-body radiator that radiates light of a color comparable to that of the light source.” (Wikipedia) A blackbody is an object that absorbs all radiation, which includes visible light, infrared light, ultraviolet light, etc.

In laymens terms, color temperature is used as a method of describing the warmth or coolness color characteristics of a light source.

Color temperature, in practice, is only useful for light sources that fall in a color spectrum of reddish/orange (yellow based) to white (blue based). This is because this spectrum corresponds closely to the radiation of a black body, whereas purples and greens do not.

This range of color can be seen when heating metal, which initially emits red light that graduates from orange to yellow, then from white to blue.

The spectrum of color temperatures is assigned numerical values, measured in degrees of Kelvin. And these values are used to describe the color emitted from fixtures when working with lighting.

When people talk about color temperature, it can easily be misconstrued as a conversation about heat. It actually refers to the color of the light that is emitted from a light fixture. The warm light is light that is more orange or red, while cool light is white and blue. The phrase color temperature comes from the color metal turns as it is heated up. First metal turns a dull red, into a lighter orange, and then turns white and then progressively darker shades of blue as it is super heated. That's why the higher color temperatures (5000K-8000K) is vibrant white and blue, while the lower color temperatures (2000K-4000K) are red and orange. This can be confusing, since the orange lower color temperatures are referred to as "warm" light, while the higher blue color temperature lights are described to as "cool" or "cold."

1. Warm white 2700K to 3900K


White 2700K luminaires with a cosy, intimate warm white light, which we recommend for use in living rooms and bedrooms. Warm white light is also considered good for relaxing, as you may want to have warmer color temperature bedside lamps to prepare for sleep, as blue light can suppress melatonin that your body naturally produces at night to help you sleep. For business applications, the warm glow creates a soft and personal, homely atmosphere in restaurants, hotels and retail stores.


White 3000K lights with a soothing warm white light, recommended for kitchens and bathrooms. Compared to 2700K, warm light at 3000K creates a relaxing atmosphere, but with a little more clarity in the surroundings, good for residential areas where you normally do tasks. For business applications, the warm glow creates a cosy, homely atmosphere in guest rooms, cafes and clothing stores.


White 3500K lights with a balanced warm white light that are best used for business applications that want to create a friendly, welcoming atmosphere that keeps people alert and focused at the same time. This desired effect fits perfectly in offices, clothing stores, hospitals, classrooms or dining areas.

2700K,Olight Toy torch: Obulb. A good sleep companion.

2. Pure White 4000K to 4900K


White 4000K has a clean, focused, pure white light that can fit well in studies, garages and kitchens. Compared to the warm light that creates relaxation, pure white makes you focused and attentive. For business applications, this is ideal for offices, grocery stores, hospitals, classrooms and jewelry boutiques, especially those selling diamonds or silver.


White 4500K has a clean, focused, slightly cold white light that provides clarity in most tasks and creates a safe working environment. We recommend white 4500K light for classrooms, jewelry boutiques, especially for the sale of diamonds or silver, grocery stores or garages.

5000K,Olight camping light: Olantern. Spice up your blissful moments

3. Cold white 5000K to 7000K


White 5000K lights with a vivid, cold white light that is suitable for high concentration and visual performance in most tasks and provides the safest working environment. We recommend white 5000K light for warehouses, hospitals, classrooms and car parks.


White 5700K with an energetic, daylight white light that is good for workplaces with specific tasks where an increase in concentration, performance and best contrast sensation is desired. Such places can be laboratories, factories and hospitals.


White 6500K lights with a warning daylight white light recommended for workplaces with specific tasks where increased concentration and performance is desired. Such places can be laboratories, factories and hospitals. Another important application is agriculture, especially the domestic economy.

6000~7000K,Olight tatical light: Warrior mini. Self-defense torch.


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