COLOR TEMPERATURE

What it is and what it means

WHAT IS COLOR TEMPERATURE

Color temperature is measured in Kelvin and is the indicator of a light source’s color. The British physicist William Thompson introduced the ‘thermodynamic temperature scale’ known as Kelvin, which is still used today. Information on color temperature can be found on every light bulb packaging nowadays. 

THE MYSTERY OF COLOR TEMPERATURE / KELVIN 

Kelvin values are not really tangible or familiar to us. So how can we visualise these numbers and what do they mean? 

CELSIUS vs. KELVIN 

The Kelvin unit generally refers to the ‘thermodynamic scale’. 0° Celsius corresponds to 273.15° Kelvin on this scale. However, color temperature is not the temperature or heat output of the light, but describes the ‘impression’ that characterises a light. The measurement is carried out using the ‘black body’ experiment, which works as follows: Solid materials begin to glow as the temperature rises; for example, iron changes from grey to a glowing red as the temperature increases. In theory, there is a ‘perfect black body’ that absorbs all the light that strikes it. When heated, it eventually begins to glow and thus emit light. The hotter it gets, the more intensely it glows, and the brighter and whiter the light it emits. From warm red tones through yellow to white and light blue. The color temperature in Kelvin therefore indicates how hot the body must be to emit a specific color of light. 

FOR REFERENCE:

 1500 K – Candle (very warm)
 3000 K – Halogen lamp (pleasant)
 5000 K – Morning/evening atmosphere
 5200 K – Midday sun
 6400 K – Overcast sky
10000 K – Blue sky (high altitude) 

All very theoretical. In summary, there are three main types of light color for light sources:

WARM WHITE

Ranges up to 3300 Kelvin. It is perceived as pleasant, warm and friendly, as it resembles the natural light of a sunset. And it brings back the feel of the good old-fashioned incandescent bulbs.

NEUTRAL WHITE

The upper limit for neutral-white light is approx. 5300 Kelvin. It creates a practical yet friendly atmosphere. Ideal for working or applying make-up.

DAYLIGHT WHITE

Above 5600 Kelvin, the light is referred to as daylight white. A stimulating light color that promotes concentration, with a high blue component. These light sources are suitable for large halls, factories, sales areas and similar environments.

AMBIENT DIMMING

Light sources with ambient dimming automatically adjust the color temperature whilst dimming! This always creates the right atmosphere in the room.

As always, the same applies here: keep your eyes open when buying light bulbs. Choose the right light for the right situation and interior.