Daylight Bulbs

What daylight means

Colour temperature is measured in kelvin, and the higher the number, the cooler and bluer the light. Warm white sits around 2700 to 3000 kelvin, cool white around 4000, and daylight from about 5000 up to 6500. At the top of that range the light is close to a bright overcast sky, which is exactly why it is good for work and less good for relaxing. Nothing about a daylight bulb is brighter in itself; it only looks brighter because the eye reads blue-white light as crisper.

Where daylight belongs

The honest rule is that daylight suits rooms where a task is being done. A workshop, a garage, a craft table, a utility room or a home office all benefit, because colours and fine detail are easier to judge. It is also popular for bathroom mirrors and for anywhere make-up is applied, since it shows colour more truthfully than warm light. In a living room or a bedroom at night, daylight usually feels clinical, and most people who fit it there end up changing it.

Daylight and the rest of the room

Mixing colour temperatures is the most common reason a room looks wrong after new bulbs go in. A single daylight bulb beside warm white ones reads as blue, and the warm ones read as yellow beside it. If a room has several fittings, fit daylight in all of them or in none. In an open-plan space, a reasonable compromise is daylight over the kitchen worktop and warm white in the living area, with enough distance between them that the eye treats them as separate rooms.

Caps and shapes

Daylight is available in the everyday caps: E27 and E14 screw, B22 bayonet and GU10 spotlight. In the GLS shape it suits a pendant or a batten in a garage; as a GU10 spotlight it throws a crisp beam onto a worktop; and in a tube it lights a workshop or a long utility room evenly. Candle-shaped daylight bulbs exist for decorative fittings, though a chandelier is rarely where daylight looks its best. Check the old bulb's cap before choosing, since the colour and the fitting are separate decisions.

Brightness and comfort

Daylight is easier on the eyes for close work, but it can feel harsh if it is too bright or aimed straight at people. Shop by lumens rather than watts and match the bulb you are replacing, then point spotlights at the surface being worked on rather than at eye level. Most of our daylight range is not dimmable, so a daylight bulb on a dimmer circuit needs to be one that is marked dimmable, or it will flicker.

Daylight tubes for workshops and garages

Long spaces such as garages, workshops and utility rooms are usually lit by tubes, and an LED tube in daylight is the modern replacement for the old fluorescent kind. It starts instantly rather than flickering into life, it does not hum, and it gives the same even, shadow-free light across a bench. Check whether the fitting needs its starter or ballast removed or bypassed before fitting an LED tube, because the product page will say, and the difference matters for a safe installation.