Correlated color temperature (CCT), measured in Kelvin, describes whether light looks warm or cool. Lower numbers are warmer; higher numbers are cooler and bluer.
| CCT (K) | Appearance | Typical use |
|---|---|---|
| 2200 to 2700 K | Warm white | Living spaces, hospitality |
| 3000 K | Soft warm white | Homes, retail |
| 3500 K | Neutral warm | Offices |
| 4000 K | Neutral to cool | Offices, schools, kitchens |
| 5000 K | Daylight | Hospitals, workshops |
| 6500 K | Cool daylight | Industrial, displays |
See the MacAdam Ellipse Chart and the CRI Reference Chart.
Comparing color temperatures
Correlated color temperature (CCT), in Kelvin, describes whether light looks warm or cool. 2700K is warm and yellowish (cozy, like an incandescent bulb); 3000K is soft warm white; 3500–4000K is neutral white; 5000K is crisp daylight; and 6500K is cool, bluish daylight. Lower numbers relax and flatter skin tones (homes, hospitality); higher numbers feel alert and clean (offices, garages, task areas). The practical rule is consistency — keep CCT the same within a room and adjacent spaces, since mismatched whites stand out immediately. CCT is separate from CRI: two lamps at the same Kelvin can render colors very differently.
Quick picks: bedrooms and living rooms 2700–3000K; kitchens and bathrooms 3000–4000K; home offices and garages 4000–5000K; display and inspection areas 5000K and up. If you’re unsure, 3000K is a safe, flattering warm-white default for living spaces and 4000K for work areas. Tunable-white fixtures let you shift along this range, which is increasingly popular for rooms used differently through the day.