Guide to LED colour temperatures

What does colour temperature mean?

Colour temperature describes the colour of light emitted from different types of bulbs. The technical term for this is correlated colour temperature (CCT). Different colour temperatures create different visual effects and are appropriate for different environments.

Colour temperature is measured in Kelvin (K) on a scale from ‘warm’ to ‘cool’:

The ‘warmer’ the light, the lower the number of Kelvin.
The ‘cooler’ the light, the higher the number of Kelvin.


2700k Extra Warm White	3000k Warm White	3500k White	4000k Cool White	6000k Daylight

Colour temperature vs Lumens

Lumens is a measurement for the brightness of light. The higher number of lumens, the brighter the light. In the past, we relied on watts (w) to show the brightness of bulb. However, with the rise of energy saving LED lighting, wattage simply doesn’t give us enough information. A standard 40w CFL bulb will produce the same amount of lumens as a 5w LED.

Does colour temperature affect Lumens?

When it comes to LEDs, yes. The higher the kelvin temperature (the cooler the light) the whiter and brighter it gets. So higher kelvin temperature means higher lumens.

You’ll often find bright, white light in workplaces and hospitals because it provides good visibility which suits working environments. The lower the colour temperature, generally, the darker and more like candle-light it is, perfect for creating a relaxing atmosphere.

However, when it comes to classic CFL style bulbs, the whiter the colour temperature (kelvin) does not mean the brighter the bulb (higher lumens).

Do LEDs have a colour temperature?

Yes. Just like other lights, LEDs come in different colour temperatures.

How do I know what colour temperature a bulb has?

The light bulb box will indicate the colour temperature, and in some case it’s also featured on the base of the actual bulb.

How accurate is the colour temperature scale?

Different manufacturers will classify the colour temperatures slightly differently. In the example below, this warm white bulb emits a yellow glow, similar to that emitted by traditional halogen bulbs. However, in the chart above this is classed as an extra warm white.

In reality there will be subtle differences between a 2700k and 3000k bulb as both will emit a soft, yellowish glow. The 2700k bulb will just be slightly yellower and warmer in hue.

What do these colour temperatures actually look like?

Extra warm white – also known as ‘soft white’ these LEDs emit a similar soft yellowy hue to that of halogen light bulbs.
Warm white – expect a similar light to that of an incandescent bulb, this is one of the most common choices for bulbs in the home as it’s suitable for relaxation rooms and busy areas such as the kitchen.
White – the LEDs with the most neutral light, the clear, sharp light provided by these bulbs make them ideal for kitchens and bathrooms in the home and office space.
Cool white – similar to ‘white’ temperature but with a slightly bluer tone.
Daylight – the closest light to natural day light. These LEDs are ideal for task lighting so are often fitted in commercial spaces.

Room-by-room guide to colour temperature in the home

As a general rule, if a room is used for relaxation then opt for a warmer temperature LED; if a room is used for tasks, such as cooking or working, opt for a cooler temperature LED. For areas that don’t fall into these categories, such as hallways, landings and stairs, choose a bulb on the warmer end of the spectrum to create a warm welcome.

Room	Ideal colour
Living room	2700k - Extra warm white
Bedroom	2700k - Extra warm white
Kitchen	3000k - Warm white
Kitchen	4000k - Cool white
Bathroom	4000k - Cool white
Task lighting	4000k - Cool white
Task lighting	6000k - Daylight

Why use “warm” light?

Warm and extra warm light helps create a comfortable and soothing atmosphere which is best for relaxing.

Why use “cool” light?

This is the general all-rounder of the light colour world. All-purpose, it’s great for activities requiring focus and well-lit areas – anything from cooking to shaving will be covered by this light.

Why use “daylight” light?

Daylight is the most energising to us because, as the name suggests, it mimics daylight. It’s great for anything that requires our upmost attention or energy. So much so that more and more workplaces are replacing their fluorescent lights with daylight LED..

Best colour temperature for office/workshops/factories

There have been several studies to find out how much LED lighting impacts the alertness and productivity of people at work. Research suggests a correlation between light levels and performance in the workplace.

Natural daylight is the best kind of lighting for optimal productivity. However, there aren’t many (if any) offices that can have access to constant daylight. The next best thing is to mimic natural daylight with artificial light. As you can see above, 6000k offers the closest we can get to natural daylight, however 4000k (cool white) can also work well.

Bright white light positively affects our mental health in addition to helping us complete intricate tasks that are much harder to undertake without artificial light. Precision working in particular will work better closer to 4000k (cool white).

LED and your eyes

Throughout a typical day, we subject our eyes to UV rays from sunlight and traditional lighting. These UV rays can cause some serious damage if you are overexposed to them.

LED bulbs are known to be a better for the eyes - this is because they emit much less damaging UV rays than other lighting. A combination of daylight mimicking LED light in an office or work environment means that your workers could be more productive and have much healthier eyes!

Choosing the LED for your home

Whether you’re looking to keep the entire house in one colour tone, or mix it up per room, it’s important to choose the right light. To help you, we’ve compiled our favourite domestic bulb for each temperature. Also take a look at our room by room guide on how to upgrade your home to LED.