Colour rendering and the colour of light

The colour of light not only affects the way decorative colours, textiles and objects look, but they also have an impact on our energy and performance levels. Choosing the right shades of colour for your home is a matter of taste and there are no absolutely right or wrong answers. Lamps also differ in their colour rendering abilities.

How we see colours

Colour is electromagnetic radiation, or light, originating from the sun or some other light source. Each shade of colour has its own wavelength. The retinal cones in the human eye sense the different wavelengths reflected on the retina: red, green and blue. Together these cells produce the sensation of colour. Daylight contains an abundance of all the wavelengths of light, all the colours of the rainbow. Seeing the different colours is based on how different surfaces reflect light of different wavelengths.

Measuring the colour of light

The colour temperature of light is measured using the Kelvin scale. A lamp's ability to render colour (Ra or CRI) and its colour temperature (K) greatly affect how the colours in the space are experienced and what kind of mood is created. The higher the Kelvin value, the bluer and colder the light is. The colour rendering index (CRI), or the Ra index, is a quantity that is used for measuring a light source's ability to render colours. When the index value is 100, the colours are rendered in the best way possible, and when it is 0, colours are not rendered at all and all we see is black and white.

Pure white light for working

Light surfaces are at their best and appear the most fresh in brighter lighting (4 000 K). Bright lights also make for excellent reading lights or working lights for the kitchen, for example. In special spaces and in high-precision work, very precise colour rendition is sometimes required. In these cases CRI 90 lamps are the best option. They make colours appear stronger and more pure with clear separation.

Warm light is relaxing

When the sun sets, the human eye sees its colour temperature as warm. As the sun sits low on the horizon, its rays have to travel the longest distance across the atmosphere. As the light travels it disperses its blue wavelengths along the way leaving only the reddish tones. It is therefore only natural that warm light in the evening has a relaxing effect that prepares the body for sleep and rest. For living spaces, you should go for warm colour temperatures and lighting that can be dimmed.
People usually prefer warmer lighting at their homes (2 700 – 3 000 K). Warm colours and the warm hues of wooden surfaces are accentuated when the light source is also warm. By replacing your old basic lamps with Decor lamps you can easily add variety to old luminaires and create a new kind of atmosphere for your home.

Daylight lamp for special situations

On a bright day, the colour temperature of natural daylight is a cool, bluish 6 500 K. Airam's daylight lamp can be used to create an atmosphere that imitates this. Daylight lamps answer the call for more natural light. These lamps are also ideal for work that requires precision, such as that of a jeweller or textile worker. In regular home use, 4 000 K is a good temperature for a reading light, for example.

Easy smart lamps

Smart lamps have changed our understanding of lighting adjustment and colour selection. Dim-to-warm lamps allow you to change the mood by dimming the lamp. The more you dim, the warmer the light becomes. 3-step smart lamps allow you to change the lighting easily with the flick of a regular light switch. Flick the switch and the light turns warm (2 700 K), bright (4 000 K) or daylight (6 500 K).

Wireless smart solutions allow you to control and adjust the lamps in your home remotely without the need for fixed dimmers. The colour temperature of these lamps is 2 700 K, which is close to the traditional warm hue of incandescent bulbs.