What the Kelvin figure tells you
A lower Kelvin figure generally looks warmer, while higher figures look cooler. The terms warm white and cool white are useful labels, but the manufacturer’s stated colour temperature gives a clearer basis for comparison between products.
Do not confuse that figure with lumens or watts. You can have a bright warm light or a low-output cool light. Start by deciding what the room should feel like and what visual tasks it needs to support.
Look at the room finishes and neighbouring lights
Look at the room finishes and neighbouring lights
Wall colours, timber, tiles and worktops can look different under different products. A sample or a good comparison in the actual room can be more useful than choosing from a photograph taken on another person’s phone.
Coordinate the colour appearance across an open-plan kitchen and dining area. The lights can serve different purposes while still looking comfortable together, especially where both areas are visible at once.
Colour rendering and glare also affect the result
Colour rendering and glare also affect the result
Food preparation, clothing, artwork and makeup can make colour rendering important. Also consider whether a bright source will be directly visible from a seated position or reflected in a screen or polished surface.
A different Kelvin figure will not cure a poor fitting position or excessive glare. Describe the task and viewing position so the electrician can discuss the arrangement, not just swap one label for another.
Fixed colour, selectable colour or dimming?
Fixed colour, selectable colour or dimming?
Some products offer selectable colour temperatures or dimming, while others have a fixed appearance. Check when and how the selection is made, what controls are required and whether the proposed dimmer works with the fittings.
If you are refreshing one part of an existing installation, provide the model details of lights you want to retain. The quotation can then distinguish a simple product change from a wider plan for switching, drivers and new positions.
What to share with your enquiry
- Room use and preferred atmosphere
- Photos of finishes in ordinary daylight
- Existing fittings you want to keep
- Product colour temperature and output
- Whether you want dimming or selectable settings
Questions answered
Is cool white lighting brighter than warm white?
No. Compare lumen output as well as colour temperature. The light distribution and room also affect the result.
Ask Max about thisCan I mix warm and cool lighting?
It can be intentional, but consider adjacent spaces and separate activities. Compare the combination before committing to a whole room.
Ask Max about thisWill dimming change the colour?
That depends on the product. Some fittings alter colour as they dim; others mainly change output. Check the exact specification.
Ask Max about thisIs warm white or cool white better for a kitchen?
Choose around the surfaces, activities and adjoining rooms rather than a universal rule. You may want clear task light at the worktop and a softer setting for dining. Compare actual products and finishes, including output and glare, before choosing the whole kitchen from a colour label.
Ask Max about thisWhy do two warm-white LED bulbs look different?
Warm white is a broad label. Products can have different stated colour temperatures and still use that description. Compare the Kelvin figures and test the combination in the room, especially when new lamps need to match fittings you are keeping.
Ask Max about thisSources and further reading
Read the original guidance relevant to this question. Building Regulations and rental-law references here relate to England.