Standing in front of a shelf of light bulbs, or scrolling through lamp listings, you will often see numbers like 2700K, 4000K or 6500K, along with terms such as "warm white", "natural white" and "cool white". These describe the colour of the light, and choosing the right one makes a big difference to how a room looks and feels. This guide explains colour temperature in plain English and helps you choose the right light for every room.
What is colour temperature?
Colour temperature describes how warm (yellow-orange) or cool (blue-white) a light appears. It's measured in Kelvin, written as K. Confusingly, lower numbers mean warmer, more golden light, and higher numbers mean cooler, bluer light.
- Around 1800K to 2200K: Very warm amber, similar to candlelight or a sunset.
- Around 2700K to 3000K: Warm white. The classic cosy glow of a traditional incandescent bulb.
- Around 3500K to 4500K: Natural or neutral white. Clean and bright without feeling clinical.
- Around 5000K to 6500K: Cool white or daylight. Crisp, bright and slightly blue.
Colour temperature is different from brightness. Brightness is measured in lumens. A warm white bulb can be very bright, and a cool white bulb can be dim. The two are separate choices.
Warm white: cosy and relaxing
Warm white light, roughly 2700K to 3000K, is the most popular choice for homes. It flatters skin tones, makes wood and fabrics look rich and inviting, and helps a room feel relaxed in the evening.
Best for: living rooms, bedrooms, dining areas and anywhere you want to unwind.
Many of our lamps glow in warm white, including the Cordless Fabric Table Lamp and the Cordless Mushroom Table Lamp. For more on creating a soft, layered glow, see our guide to hygge lighting.
Natural white: balanced and practical
Natural white, around 4000K, sits between warm and cool. It's bright and clear, so colours look true, but it doesn't feel as stark as daylight bulbs.
Best for: kitchens, home offices, bathrooms, utility rooms and dressing areas where you need to see clearly.
Cool white and daylight: crisp and focused
Cool white and daylight bulbs, 5000K and above, give a bright, bluish light similar to a clear midday sky. They can help with detailed work and feel energising, but in living spaces after dark they can seem harsh and clinical.
Best for: garages, workshops, task lighting for crafts and detailed work, and some bathroom mirrors.
Colour temperature and sleep
There's a general consensus that bright, cool, blue-rich light in the evening isn't ideal for winding down, while warmer, dimmer light suits the hours before bed. You don't need to be scientific about it: simply favour warm, low light in bedrooms and living spaces in the evening, and save brighter, cooler light for daytime tasks. A soft bedside lamp or a gentle glow such as the Sunset Projection Lamp can be part of a calming evening routine. Read more in our guide to sunset lamps.
Room-by-room guide
Living room
Warm white, 2700K to 3000K. Layer several lamps rather than relying on one bright ceiling light. See how to light a small living room.
Bedroom
Warm white, 2700K or lower, with dimming if possible. A brighter, adjustable lamp is useful for reading in bed.
Kitchen
Natural white, 3500K to 4000K, for worktops and cooking, with warmer light over a dining table. Stick-on lights such as our Stick-On LED Spotlights work well under cabinets.
Bathroom
Natural white around the mirror for grooming. Consider warmer light for relaxing baths.
Home office or desk
Natural to cool white, 4000K to 5000K, for focus during the day. An adjustable lamp like our Adjustable LED Desk Lamp lets you direct the light exactly where you need it.
Hallways and stairs
Warm to natural white. Motion-sensor lights such as our Motion Sensor Night Lights provide a gentle glow at night without dazzling.
The best of both: adjustable lamps
Many modern LED lamps let you switch between warm, natural and cool white with a touch. This is particularly useful in multi-purpose rooms, where you might work at a desk in the afternoon and relax in the same space in the evening. Several of our rechargeable lamps, including the Cordless Touch Table Lamp, offer adjustable colour modes and brightness. Check each product's description for its exact settings.
Mixing colour temperatures
A common mistake is mixing very different colour temperatures in the same room, which can make one corner look yellow and another look blue. Try to keep lights within a room fairly consistent, especially lights that can be seen together. If you do mix, keep cooler light for focused tasks and warmer light for ambience.
What about CRI?
You may also see CRI, the Colour Rendering Index. This describes how accurately a light shows colours compared with natural daylight, on a scale up to 100. A higher CRI makes food, fabrics and skin tones look more natural. It's worth considering for kitchens, dressing areas and anywhere colour matters.
Quick reference
- Relax: warm white, 2700K to 3000K.
- Everyday tasks: natural white, 3500K to 4500K.
- Detailed work: cool white, 5000K and above.
- Evenings: warm and dim.
- Multi-purpose rooms: adjustable colour modes.
In summary
There's no single "right" colour of light, only the right light for each room and time of day. As a simple rule, choose warm white where you relax and natural white where you work. Explore our lighting collection and our lighting guide to find the right lamp for every corner of your home.