4000K Light Colour Explained: 3000K vs 4000K vs 6000K
Light colour tells you whether light looks warm, neutral or cool. It is measured in kelvin (K): the higher the value, the cooler and bluer the light. Offices, medical practices, workshops and hair salons usually choose 4000 K neutral white, while reception areas, hotels and restaurants tend to use 3000 K warm white.
This guide covers the kelvin chart, a direct comparison of 3000 K and 4000 K, recommendations for individual rooms and the values the European standard sets for workplaces.
At a glance
What light colour means
Light colour, also called colour temperature, describes the colour impression a light source creates. The kelvin scale can seem back to front at first: a high value means cool, bluish light, a low value warm, yellowish light. A candle is around 1800 K, a classic incandescent bulb about 2700 K and the midday sun 5500 to 6000 K.
The three groups come from EN 12464-1: warm white is below 3300 K, neutral white between 3300 and 5300 K, and daylight white above that. Within each group the differences are noticeable. 3500 K, for example, already counts as neutral white under the standard, yet looks clearly warmer than 4000 K.
Kelvin is not brightness. How bright a luminaire is depends on its lumen output. A 3000 K and a 4000 K luminaire with the same luminous flux are equally bright, even if the cooler light often looks a little brighter.
Light colour chart: from warm white to daylight white
The chart shows the common kelvin values, how they look and where they are typically used.
| Kelvin | Name | Appearance | Typical use |
|---|---|---|---|
| 2700 K | Warm white | very warm, yellowish | hotel rooms, restaurants, lounges, living areas |
| 3000 K | Warm white | warm, slightly yellowish | reception, lobby, showroom, fashion and furniture retail |
| 3500 K | Neutral white, warm end | balanced, still warm | corridors, exhibition spaces, open-plan kitchens |
| 4000 K | Neutral white | clear, natural white | offices, medical practices, schools, workshops, hair salons |
| 5000 K | Neutral white, cool end | bright, slightly bluish | dental practices, inspection stations, warehouses |
| 5700 K | Daylight white | cool | quality control, precision assembly |
| 6000 to 6500 K | Daylight white | very cool, bluish white | inspection areas, clean rooms, special applications |
Browse luminaires by colour temperature: 2700 K, 3500 K panel with Ra 97, 4500 K, 5500 K and 6000 K.
The three most important light colours
In commercial projects the choice almost always comes down to one of three light colours. Once you know the differences, most rooms can be assigned correctly without lengthy planning.
Inviting light that recalls the incandescent bulb. It belongs wherever atmosphere matters more than visual acuity: reception, showroom, restaurant, hotel.
3000 K compared with 4000 KThe standard for workspaces. Colours look neither yellowish nor bluish, and the light keeps people alert without feeling cold. Offices, practices, schools, workshops, salons.
More about 4000 KCrisp, bluish white light for workstations where every detail counts, such as quality control. Across large areas it quickly feels uncomfortable.
Luminaires in 6000 K4000 K light colour: neutral white for workspaces
4000 K is the usual light colour in offices, medical practices and workshops. The light looks clear and keeps people alert, but without the coolness of 6000 K. Skin, wood, fabric and paper look the way you know them, because the colour impression is shifted neither towards yellow nor towards blue.
At 4000 K you are right in the middle of the neutral white range defined by EN 12464-1. If you are unsure which light colour a workspace needs, 4000 K is rarely the wrong choice.
Why hair salons almost always choose 4000 K
We have fitted more than 100 hair salons with LED lighting, and over 90 per cent of these customers chose 4000 K neutral white. There are three reasons for this.
Judging colour accurately
A colour treatment should look the same in the salon as it does later in daylight. Under 3000 K shades look too warm and reddish, under 6000 K too cool. 4000 K sits in between.
Long working days
Salon staff spend many hours under artificial light. Neutral white keeps them focused without the glare of daylight white.
Comfortable for clients
Many clients find 6000 K cold and clinical. 4000 K feels professional yet friendly, and clients see themselves in the mirror as they look outside.
Case study: Haarscharf, Solingen
Hair salon · LED ceiling lights 120 × 30 cm
The salon does colour treatments every day. Its existing LED lights had poor colour rendering, so hair colours looked different inside than they did outside. We installed ceiling lights with Ra 94 to 95 whose light colour can be set to 3000, 3500 or 4000 K. The colour stations run on neutral white working light, the reception area on the warmer setting.
LED lighting for hair salonsWhere else 4000 K is the standard
Recessed spotlights in 4000 K with Ra 98
Where neutral white light and very natural colours need to come together, for instance in salons, medical practices, exhibitions and retail, we use 90 mm recessed spotlights with a colour rendering index of Ra 98. The value is measured with a spectrometer and is well above the usual Ra 90. The spotlights are dimmable, flicker-free and fit ceiling cut-outs of roughly 70 to 85 mm. The round and square 8 W versions deliver around 700 lumens at 4000 K with a 36° beam angle.
All models are listed in the category dimmable LED downlights with CRI 98.
Dimming 4000 K
Fixed 4000 K luminaires can be dimmed smoothly with DALI control: full output in the morning, a little lower in the late afternoon. The light colour stays the same. If you also want to switch to warmer light in the evening, you need luminaires with adjustable light colour, such as the luminaires with colour change from 3000 to 6000 K.
3000 K or 4000 K: a direct comparison
Warm white or neutral white is the most common question in lighting design. The table compares the two.
| Feature | 3000 K warm white | 4000 K neutral white |
|---|---|---|
| Colour impression | warm, yellowish | neutral, natural white |
| Effect | cosy, relaxed | businesslike, focused |
| Typical rooms | reception, hotel, restaurant, living areas | office, practice, workshop, school, hair salon |
| In the evening | favourable, little blue content | rather activating |
| Colour rendering | warm tones such as wood and skin look especially good | all colours neutral |
| Recommended Ra | Ra 80 or higher, Ra 90 or higher in retail | Ra 80 or higher, Ra 90 or higher where colours are judged |
Rule of thumb: if a room is mainly for welcoming people and relaxing, choose 3000 K. If it is about concentration and visual tasks, choose 4000 K. For rooms that have to do both, there are luminaires with adjustable light colour.
Which light colour for which room?
These recommendations apply to general lighting. Individual workstations may differ, for example an inspection station in an otherwise neutral white hall.
Offices and screen work
EN 12464-1 requires 500 lx on the work surface for writing, reading and screen work, colour rendering of Ra 80 or higher and glare limited to UGR 19.
LED panels for officesMeeting and seminar rooms
Neutral white during the day for presentations and work, warmer for informal meetings or evening events. Switchable luminaires are a good fit.
DALI LED panelsMedical practices and laboratories
Neutral to slightly cool, with colour rendering of Ra 90 or higher. For matching tooth shades, daylight-like light from 5000 K is recommended.
5000 K panel, Ra 92Hair salons
4000 K at the colour stations, Ra 90 or better. Over 90 per cent of our salon customers choose this light colour. Reception and waiting areas can be warmer.
Lighting for salonsWorkshops and production
4000 K for assembly and general lighting, 5000 to 6000 K at inspection and precision workstations. Where colours are judged, for example in paint shops, Ra 90 or more.
Planning high bay lightingWarehouses and halls
Neutral white with Ra 80 is enough for aisles, picking and dispatch. Illuminance and controls matter more here than the light colour.
High bay lighting guideRetail
3000 K for fashion, furniture and food, because goods look warmer and more upmarket. 4000 K for electronics, tools and car parts, where detail and colour accuracy count.
Track lightingHotels, restaurants, reception
Warm white creates the calm atmosphere guests expect. 3000 K is common in hotel rooms, lounges and spa areas, 2700 K in many restaurants.
Luminaires in 2700 KKitchens and commercial kitchens
3000 K in the dining area so that food looks appetising. 4000 K above worktops, chopping boards and hobs in professional kitchens.
Adjustable light colourBathrooms and washrooms
3500 to 4000 K for a clear view with a pleasant mood. At the mirror, Ra 90 or better so that make-up and shaving work out. In wet areas, look for IP44 or higher.
Downlights with IP protectionOutdoor areas and car parks
4000 K for car parks, driveways and paths with good visibility. Where neighbours, gardens or insects are affected, 3000 K or warmer is the gentler choice, because the light contains less blue.
Outdoor lights with motion detectorInspection and quality control
Cool, high-contrast light combined with high colour rendering. Better used as task lighting than for the whole room.
Luminaires in 5500 KAdjustable light colour and DALI
Luminaires with adjustable light colour, often called CCT (correlated colour temperature), cover several kelvin values with a single model. They come in two types, and it is worth telling them apart before you buy.
Switchable
The light colour is usually selected with a slide switch on the luminaire or the driver, for example 3000, 4000 or 5700 K. This normally happens once, during installation. The advantage: one luminaire type suits different rooms, and the decision can be made on site.
Example: 115 mm spotlight, 2700 to 4000 KContinuous (tunable white)
The light colour can be changed during operation, by remote control or through a control system such as DALI DT8. The light can then be neutral white during the day and warm white in the evening, automatically by time of day if you wish.
Luminaires with colour changeAdjustable light colour is particularly worthwhile in these cases:
- A room is used in different ways, for example as a seminar room by day and for events in the evening.
- Staff or shifts have different preferences.
- You want a single luminaire type for several areas.
- During a refurbishment, the future use of the space is not yet settled.
- 3000–6000 KColour change from 3000 to 6000 Koffices, meeting rooms, retail
- adjustable85 mm spot, IP65, adjustable light colouralso for bathrooms and wet areas
- adjustableRound ceiling light 60 cm, DALI30 % indirect light, UGR 19
- DALIDALI LED panelsfor offices and meeting rooms
What DALI does
DALI (Digital Addressable Lighting Interface) is a standard for digital lighting control. Every luminaire gets an address and can be controlled individually or in groups without rewiring. Lighting scenes for presentations, cleaning or evening use can be saved and recalled by push button, timer or sensor. Controlling the light colour requires luminaires to DALI DT8.
In our shop you will find DALI recessed lights and ceiling spots, DALI downlights in five sizes and our full range of DALI luminaires.
Colour rendering: as important as light colour
Light colour says nothing about how natural colours look under the light. That is described by the colour rendering index, CRI, often given as the Ra value. The scale goes up to 100, the value of the reference light source. The closer a luminaire gets to 100, the more natural colours appear.
- below Ra 80only where colour does not matter
- Ra 80–89minimum for offices, schools, practices
- Ra 90–94retail, salons, inspection
- Ra 95 and abovecolour matching, cosmetics, galleries
| Ra value | Rating | Typical use |
|---|---|---|
| below 80 | basic | circulation areas, storage without colour distinction |
| 80 to 89 | good | offices, schools, practices, workshops; the minimum for office work under EN 12464-1 |
| 90 to 94 | very good | retail, exhibitions, inspection stations, hair salons |
| 95 and above | excellent | printing, colour matching, medicine, cosmetics, galleries |
Light colour and colour rendering belong together. Two 4000 K luminaires with Ra 80 and Ra 95 both give neutral white light, but under the second one colours look far more natural and saturated. In retail, combining 3000 K with Ra 90 or more makes goods look upmarket.
- Ra 90LED panels with Ra 90for offices, practices and meeting rooms
- Ra 9890 mm recessed spotlights with Ra 98in 4000 K, round, square, DALI
Light colour in the evening
Light also affects our internal clock. The higher the blue content, the more strongly light suppresses the sleep hormone melatonin. During the day this helps concentration; in the evening it can make it harder to fall asleep. Warm white light around 2700 to 3000 K has little blue content and is far less disruptive.
For offices used into the evening and for home offices: choose light that can be dimmed and switched to 3000 K at the end of the working day, for example with colour-changing luminaires or a DALI system with time control.
Frequently asked questions about light colour
Which light colour is best for an office?
4000 K neutral white. The light looks natural and supports concentration without feeling cold. For screen work, the luminaires should also be low-glare (UGR 19), flicker-free and offer colour rendering of Ra 80 or higher.
What is the difference between 3000 K and 4000 K?
3000 K looks warm and yellowish, similar to an incandescent bulb. 4000 K looks neutral white and cooler. 3000 K suits reception areas, hotels and restaurants, 4000 K workspaces that call for concentration.
Is 4000 K cool white?
No. 4000 K is neutral white. Light only counts as cool or daylight white from around 5300 K. The impression of “cold” light often comes from being used to warm white light at home.
Is 4000 K brighter than 3000 K?
Not automatically. Brightness depends on the luminous flux in lumens. With the same output, 4000 K often looks a little brighter and crisper, because cooler light creates more contrast.
What do warm white, neutral white and daylight white mean?
EN 12464-1 divides light colours into three groups: warm white below 3300 K, neutral white from 3300 to 5300 K and daylight white above 5300 K.
What do codes such as 830, 840 or 940 mean?
The three-digit code combines colour rendering and light colour. The first digit stands for colour rendering (8 for Ra 80 to 89, 9 for Ra 90 and above), the other two for the light colour in hundreds of kelvin. 840 therefore means Ra 80 or higher at 4000 K, and 930 means Ra 90 or higher at 3000 K.
Which light colour for a workshop or warehouse?
4000 K for general lighting, 5000 to 6000 K at inspection and precision workstations. For warehouses without special visual tasks, 4000 K with Ra 80 is enough. More on planning in our high bay lighting guide.
Why do hairdressers almost always choose 4000 K?
Over 90 per cent of our salon customers have chosen 4000 K. Under 4000 K hair colours look the way they do in daylight, under 3000 K too warm and under 6000 K too cool. Neutral white also keeps staff focused through long working days and feels friendlier to clients than daylight white. Colour rendering of Ra 90 or higher is important.
3000 K or 4000 K for retail?
It depends on the goods. 3000 K suits fashion, furniture and food, making products look inviting and upmarket. 4000 K is better for electronics, tools or car parts, where detail and colour accuracy matter more than atmosphere.
Can I mix luminaires with different kelvin values?
Better not within one room or field of view. Very different light colours side by side, such as 3000 K and 6000 K, look restless. If you need different light colours, choose luminaires whose light colour can be changed together.
What is CCT and what does adjustable light colour mean?
CCT stands for correlated colour temperature, the colour temperature in kelvin. Luminaires with adjustable light colour can be set to several values, for example 3000, 4000 and 5700 K. Switchable models do this with a switch, tunable white models continuously by remote control or a control system.
Is 4000 K suitable for a living room?
For general lighting in a living room, usually not; 2700 to 3000 K feels cosier there. 4000 K suits worktops in kitchens, utility rooms, workshops or a study.
What colour temperature does daylight have?
It changes over the day. In the morning and evening the sun is much warmer, at midday it is around 5500 to 6000 K, and under an overcast sky the light is cooler still at 6500 K and above.
Talk to us about the right light colour
Not sure which light colour and colour rendering your space needs? We will advise you on luminaire, light colour and controls.
- Personal advice, easy to reach
- Highly reliable products
- High standards of light quality
- Many projects with DALI and KNX
Sources and further reading
- EN 12464-1:2021, Light and lighting – Lighting of work places – Part 1: Indoor work places. Light colour groups, illuminance, Ra values and UGR for office work.
- LED high bay lighting: planning and calculator: light colour and colour rendering in production halls, warehouses and sales areas
- LED panels for professional use
- Office lighting
