Luminous color – the right color temperature for optimal lighting 21140 back to overview

Luminous color – the right color temperature for optimal lighting

You are looking for new luminaires or replacements for lamps but you just can’t deal with the terms „kelvin“, „warm white“, „neutral white“ and „daylight white“? 

We will explain to you the key features that are important to know for choosing the right color temperature.

The luminous color plays an important role, especially since LED is getting more and more popular. Depending on the model, there suddenly are distinctions of the luminous color. However, what sounds initially complicated may offer huge benefits to you: with an ample range of luminous colors, you can steer effect and function of your illumination according to the area of application.


What is the luminous color?

Luminous color describes the color of a self-luminous source. This color is defined by the score of color temperature, indicated by the specification in Kelvin (K).

Depending on the spectral composition of light, different colors of white light are created. Roughly, you can distinguish between three luminous colours:

  • Warm white light: ≤ 3.300 K
  • Neutral white light: 3.300 bis 5.300 K
  • Cold white or daylight white light: ≥5.300 K

Basically, we can summarize as follows: the higher the indication in Kelvin, the colder is the effect of your luminous source.

We explain to you which luminous color is adequate for the various areas of application. But first, we would like to draw your attention to another quality feature which you should consider when choosing your new (replacement-) luminaires: the color rendering index.


What is the color rendering index?

The color rendering index stipulates the quality of artificial light compared to natural light. Its specification is indicated by the score Ra (Referenzindex allgemein) or in English, CRI (Color Rendering Index).

The composition of the spectral colors of light does not only have impact on its own color. It also influences colors of objects rendered by reflection. Light containing all spectral colors offers the most natural perception of the environment.

This means: the higher the index in Ra/CRI, the most natural is the color rendered (the sun has with Ra 100 the highest and thus most natural index).


The right luminous color: a combination of color temperature and color rendering index

Often the luminous color is specified by a triple digit code. The first figure relates to the color rendering index whereas the second and third figure refer to the color temperature.


A lamp having a luminous color of 840 renders a good quality of color with CRI 80 and has a neutral white light color with 4.000 K.


The right luminous color for your application

The different luminous colors have impact on the effect of light. Hence, they offer excellent potential to create ideal working conditions or to arrange for individual and comfortable illumination at home.

Regarding the color rendering index, a high score is important for all purposes needing most possible natural conditions. This concerns for example sales areas, workshops, varnishing or painting halls etc.

The choice of the right color temperature also depends on its application.


Warm white light is most similar to the light of the former incandescent lamps (2.700 K). It creates a comfortable and homy ambience and is thus perfectly suited for rooms where people would like to relax.

Neutral white light is ideal for office spaces, home offices, kitchen and bathrooms, but also for sales areas. It offers an unemotional atmosphere where you feel comfortable.

Cold white light is the light being most similar to daylight (according to daylight time ≥ 5.500 K). It is recommendable for usable or basement spaces or places requiring good conditions for concentration.


The choice of ideal illumination highly depends on individual sensitiveness especially for areas having no legal regulations for lighting requirements. Should you feel uncertain, we recommend choosing LED because it is controllable for its luminous color and easy to steer.

In this video we present the CASAMBI CASA BULB. This product is the perfect solution to create different lighting atmospheres. Via app, stepless variable luminous colors can be set at discretion.


The luminous color and the human biorhythm

The daily, natural course of the sun has an impact on the biological rhythm of all creatures. However, this is not the case for many places. Most people are in closed rooms with constant same lighting most of the day.

Research and studies discovered a connection between natural daylight conditions and the human capacity of concentration and general well-being.

Human Centric Lighting (HCL) offers opportunities to simulate the natural course of the sun and to create a positive influence on performance and health condition by choosing the right luminous color.

The following video gives more information on the topic HCL. It also explains which light control is adequate for illumination of your office with respect to a natural daily rhythm.