Colour Temperature

White, white or white?! When choosing light fittings the different variations of white light available can be confusing. This guide explains the differences in colour temperature and the effect they have on our wellbeing.

The importance of choosing the right colour temperature cannot be underestimated - the different options not only have the power to change the ambience of a space, but also have an impact on our wellbeing.

Colour temperature is based on the varying colours of natural light throughout the day and measured in degrees of Kelvin (K). Lighting for residential and commercial environments tend to range from 2000K - 6000K. 

2000K is a very warm white and looks yellow to orange like at sunset, whereas 6000K, is a cool blue white similar to daylight at midday. It is rather confusing that as the temperature heats up the colour cools down but one way to remember it is to think of metal being heated. As it starts to get hot the it glows a beautiful orange, and as it reaches its melting point it becomes white hot.

Our experience of different colours of white light is not only visual as it also has an impact on our wellbeing and affects our body clock. It is scientifically proven that too much blue-rich light in the evening (e.g. from smartphones), can have a negative impact our performance, metabolic function and immune response as it suppresses our melatonin production. Therefore the variations in colour temperature are best used at particular times of day or for specific functions. For example, cool whites are great in offices as they enhance productivity, whilst the warmer whites are more relaxing in the evening and help to prepare the body for sleep.

The display above demonstrates the variations in colour temperatures from extra warm white through to daylight white. Each one creates a different atmosphere as well as changing how we view the colours of the same glass vase. From left to right - 

Extra warm white - 2500K

This is similar to the colour of halogen light. 2500K and 2700K are great for living rooms and bedrooms as it is a restful colour and prepares the body for bedtime.

Warm white - 3000K

This is commonly used throughout the home environment and is best for kitchens, studys and utility rooms, where you may want a slightly whiter white for task lighting than the extra warm white of 2700K.

Natural white - 4000K

This is mainly used in offices and rooms which are in use during the day. The whiter colour temperatures contain more blue light and this stimulates our system. It can interrupt our sleep cycle if viewed late at night.

Daylight white - 5000K

Daylight white is 5000K-6000K and is usually used for painting and needlework and other activities where the user needs to see the true colours, as they are in actual daylight.

When varying colours of white lighting are used within the same space, for example 3000K and 4000K, the difference jars the eye and draws attention to the light source, rather than the surfaces being lit. So whatever your choice, stick with the same colour temperature throughout in order to create a harmonious lighting scheme.