At what temperature does stainless steel glow red

Light color temperature (Kelvin)

The color temperature, also called light color, describes the natural color of the light from a light source. It indicates whether the light is more yellowish-warm or bluish-cool, and is measured in Kelvin (K). The following applies: the higher the value, the colder the light color. A distinction is therefore made between warm and cold color temperatures. Values ​​up to 3,300 K describe warm, yellow-reddish light moods. Higher values ​​make it clear that the blue component predominates in the light, which leads to a cooler, cold white color impression. On the quality of the Colour reproduction the light color of a lamp does not allow any conclusions to be drawn. This means that lamps with the same color temperature can have very different CRI values.

Light color temperatures not only influence the room atmosphere, but also to a decisive extent our well-being. When choosing the right light source, the light color is therefore of great importance. It is based on subjective preferences, but also on the respective area of ​​application. The biological effectiveness of artificial lighting plays an important role in this context. As we now know, warmer color temperatures have a calming and relaxing effect, while cooler temperatures are stimulating and stimulating. This is related to the natural cycle of daylight, which our internal clock serves as an orientation. The activating, or even dampening, effect of light must therefore be taken into account when planning lighting. For the living area, warmer light colors are recommended than for the office, where it is important to create a lighting atmosphere that is conducive to efficient work performance. Conversely, in the living room and in the sleeping area, in order to prepare the body for a restful sleep in the evening, lower light colors should be chosen, which are also linked to a lower illuminance. A good lighting designer knows about the effectiveness of light and tailors the interior lighting precisely to the purpose of the facility.

The areas of light colors and their application

The light color of lamps is basically divided into three areas: warm white light describes values ​​up to 3,300 K, neutral white light light colors between 3,300 and 5,300 K. Color temperatures of more than 5,300 K are similar to the spectrum of daylight and are therefore referred to as daylight white.

Warm white (below 3,300 K):

Warm white light is perceived as cozy and is therefore ideal for lighting in the living area. This is especially true for color temperatures between 2,700 and 3,000 K - a spectrum that can be compared with the light of classic incandescent lamps and halogen lamps. In its perception of being particularly pleasant, it is often referred to as a "comfortable temperature". Values ​​below 2,700 K correspond to a reddish-warm color temperature that is achieved when dimming incandescent lamps. Dimmable LEDs, whose light color does not change by default when dimmed, are only able to imitate this effect if they have the so-called Dim-to-warm technology (also called warm dimming). This has the effect that the color temperature of the LED is reduced to up to 2,000 K when dimmed. Light sources with warm white light color are perfectly suitable for your own four walls, but also hotels, restaurants and sales rooms such as bakeries.

2,700 or 3,000 Kelvin? This decision is, on the one hand, a matter of taste and, on the other hand, it depends on the surroundings: When choosing the light color, the color of the room to be illuminated also plays a role. This includes all areas of the interior, i.e. ceilings, walls, floors and furniture. If there is a lot of wood or if the walls are painted in yellow or earth tones, a color temperature of 2,700 K should be avoided and 3,000 K should be chosen instead. The yellowish color impression of the light would otherwise only be unnecessarily intensified by the surrounding colors. Conversely, in an interior with cooler tones, a color temperature of 2,700 K is recommended, as it gives the environment additional warmth. The color of the surroundings and the natural daylight is also a reason why light sources with 3,000 K are preferred in southern latitudes, whereas in northern climes warmer 2,700 K.

Neutral white (3,300 to 5,300 K):

Neutral white or cool white light is perceived as "factual" and pleasantly bright. It has a stimulating effect, reduces tiredness and increases concentration. Since it comes closer to daylight than warm white light, it gives the body a pleasant kick of freshness. It is therefore recommended as work light - in the office, but also in the home office. Light sources with a neutral white color temperature are also the right choice in the kitchen, where the task is to effectively illuminate the work surface. In addition, they are ideal for bathrooms, corridors, doctor's offices, sales rooms and the outdoor area.

Daylight white (over 5,300 K):

Light colors beyond 5,300 K are similar to natural daylight. While they are perceived as pleasant in nature, due to their high proportion of blue they are not suitable for all types of interior space. Cold white color temperatures are ideal for areas of application in which a light atmosphere that promotes concentration is important. This applies, for example, to hospitals, offices, industrial premises or lecture halls. However, they are not suitable for living areas.

An overview of the color temperatures of various light sources

Light source
Color temperature
candle1,500 Kelvin
Lightbulb2,700 to 2,900 Kelvin
Halogen lamp (230 V)2,700 to 2,800 Kelvin
Halogen lamp (12 V)3,000 to 3,200 Kelvin
Fluorescent lamp2,800 to 6,000 Kelvin
LEDs2,700 to 8,000 Kelvin
Morning and evening sun5,000 Kelvin
Midday sun5,500 to 5,800 Kelvin


Modern LEDs are able to cover the full spectrum from warm white to daylight white. In this way, they can be used in a variety of ways and can be used both at home and in the contract sector. Many LED lights are also more modern Color change function