By Emmanuel Sauvage · Updated
Technical guide
Colour temperature (Kelvin)
Measured in kelvin (K), the correlated colour temperature describes how warm (yellow) or cool (blue) white light looks. Lower = warmer.
Labels decoded
| Kelvin | UK packaging | US packaging | Typical use |
|---|---|---|---|
| 2200–2700K | Extra warm / warm white | Soft white | Living room, bedroom, dining |
| 3000K | Warm white | Warm white / bright white (low end) | Kitchen with wood, hallways, bathrooms |
| 4000K | Cool white | Bright white / cool white | Kitchen worktops, garage, home office |
| 5000–6500K | Daylight | Daylight | Workshop, task lighting, photo work |
The colour code on professional lamps combines CRI and Kelvin: "827" = CRI 80+, 2700K; "930" = CRI 90+, 3000K; "840" = CRI 80+, 4000K.
Room by room
- Living room and bedroom: 2700K. Evening light above 4000K is perceived as harsh in living spaces.
- Kitchen: 3000K ambient plus 4000K under-cabinet for tasks, or 3000K throughout if open-plan.
- Bathroom mirror: 3000–4000K with CRI 90 for make-up and shaving (see CRI).
- Home office: 4000K at the desk.
- Garage and workshop: 4000–5000K.
Keep one temperature per room: mixing 2700K and 4000K in the same field of view makes both look wrong.
Examples
US · E26 120 V
Philips Ultra Definition LED A19, 8W, 2700K (8-pack)
Listing: 60 W equivalent, 800 lm, E26 base, dimmable, flicker-free. Listed as CRI 95.
Check price on Amazon USUS · E26 120 V
Philips Ultra Definition LED A19, 8W, 5000K daylight (8-pack)
Listing: 800 lm (8 W = 60 W), dimmable, frosted, flicker-free.
Check price on Amazon USUK · GU10 230 V
Philips CorePro LED GU10 4W, 4000K, dimmable (10-pack)
Listing: 50 W halogen replacement, 350 lm, 36° beam, CRI 80, dimmable with compatible dimmers, energy class F.
Check price on Amazon UKProduct data below is taken from the manufacturer's listing on Amazon, checked on 22 October 2026. Prices change: check the current price before buying. As an Amazon Associate I earn from qualifying purchases.