Which Colour Temperature Is Best For Lighting?
Asking “Which colour temperature should I choose?” is very similar to asking “What colour should I paint my wall?”
There really is no right or wrong answer, it mostly comes down to personal preference. And when there are a myriad of options to consider when purchasing lighting - such as the type of fitting, cost, lumens, brand and warranty - colour temperature may not be at top of your list of priorities.
Nevertheless, colour temperature can have a noticeable effect on the feel of a space, and if you have to pick one, it’s good to know what it's all about. Here are a few tips to help you make an educated choice.
Colour "temperature" terms are the opposite to heat temperature.
Confusingly, the way we talk about colour temperature is opposite to the way we talk about heat temperature.
The higher the colour temperature on the Kelvin Scale, the cooler the colour. The lower the colour temperature, the warmer the colour.
The only connection to heat is that candlelight and firelight have lower colour temperatures on the Kelvin Scale, and that’s probably why we describe lower colour temperatures as “warm”.
Note that a benefit of LED lighting is that it produces far less waste heat than other lighting technologies, no matter the colour temperature.
When choosing a colour temperature, numbers matter.
Colour temperature is usually expressed as a four digit number in the unit kelvin, using the symbol K, for example “3000K” or “6500K”.
Manufacturers of lighting like to use helpful descriptive words such as “warm white”, “cool white” or “daylight” to differentiate between their products. However as there is no industry standard for these phrases, it's important not to rely on them too heavily. One brand’s 5000K could be described as “daylight”, whereas another brand’s bulb could be described as “cool white”. In fact, they may even be some variation within one brand's different products.
Therefore, if you’re trying to match or replace a specific colour temperature, or if you’re comparing two products from different brands, it's best to ignore the descriptive word and only look at the K number.
If the packaging or online description doesn’t provide a number, ask the retailer for clarification, as it could mean anything!
Learn the international colour temperature code (it's easier than it looks).
Be aware that colour temperature is often specified as a code like "830" or "965". This is often the case with LED or Fluro Tubes. These codes simply combine two lighting specification into one - that of colour rendition and colour temperature.
The first number refers to colour rendition:
- 8 = colour rendering index Ra 80 – 89
- 9 = colour rendering index Ra 90 – 100
The second and third numbers refer to colour temperature, for example:
- 27 = 2700K
- 30 = 3000K
- 40 = 4000K
- 50 = 5000K
- 65 = 6500K
Generally, “warm” is considered atmospheric, “cool” is considered practical.
Just like certain colours have cultural connotations (e.g. red = passion, blue = calm), the choice of colour temperature can be used to create certain moods in your space.
Lower colour temperatures are more orangey and are considered to be “warm”, because they remind us of candlelight. Combined with low key lighting in bedrooms, cafes and restaurants, warm colour temperatures can be used to create a cosy atmosphere.
This vintage style filament LED bulb comes in 2700K, perfect for cafe lighting.
Higher colour temperatures tend towards blue and are considered “cool”. Daylight is a high 5500K, so if you want to recreate the feeling of a bright sunny day, go for a higher colour temperature. Higher colour temperatures are generally perceived as brighter, so they’re great for areas that are practical workspaces, like kitchens and offices. (Note: if you’re looking for more brightness however - the specification to check for is lumens, not colour temperature.)
A downside to high colour temperatures is that they could be considered too “stark” or “sterile”, like a hospital or a 7-Eleven store.
This 4000K LED panel (to replace fluorescent fittings) is used in offices.
With colour temperature - consistency is key.
Colour discrepancies are more obvious when two bulbs of different colours are placed next to each other. Mismatched lighting can seem incongruous; so whatever you choose, try to keep the colour consistent within a space. For example, all the down-lights in one ceiling should match.
This may create a problem in open plan living, where the kitchen and living areas are in the same room. A cool colour temperature like 4000K might work in the kitchen, but could seem too stark for the lounge. Likewise, an atmospheric warm colour temperature like 2700K might be great for the living area, but not practical enough for the working in the kitchen. In this case, meeting in the middle at 3000K is a good compromise and keeps the light consistent throughout the space.
That’s probably why 3000K is the highest selling colour temperature for the LED downlights we sell; its versatility makes it a popular choice.
That being said, don’t be afraid to use different colour temperatures in separate rooms if you need to. You could also have one colour temperature for the ceiling lights, and another for floor and table lamps, switching between the two modes of lighting for different occasions.
When in doubt, stick with what you are used to.
If you're upgrading from an older lighting technology to LED, ask yourself, what are you replacing? Do you like what is there? If so, then there’s no harm in trying to match it. Check the small print on the bulbs or tubes that you own to see what their colour temperature is.
Luckily for this reason, most LED retrofit solutions already have colour temperatures that match what they are commonly replacing.
If you can’t find the exact match, don’t worry, near enough should be good enough, as long as the colours are consistent within the space (see point above).
Can’t decide? Try new “tunable white” or “RGB” technology.
Now some lights can even change their colour temperature. Take the Osram Lightify series of products, where you can control brightness, colour, and colour temperature of your light bulbs (depending on light bulb product) via a phone app. The “tunable white” bulbs let you control standard colour temperatures, whereas bulbs with “RGB” (red, green, blue) functionality are great for parties or more creative applications.
The Osram Lightify App lets you dial in the colour temperature of your light.