Home · 2026-04-01
Understanding Colour Temperature: A Complete Guide
2700K, 4000K, 6500K — what do these numbers actually mean, and which should you use where?
6 min read
What Is Colour Temperature?
Colour temperature is measured in Kelvin (K). Lower numbers (2700K) produce warm, yellowish light similar to candlelight. Higher numbers (5000K+) produce cool, bluish light similar to daylight. Your brain responds differently to each.
Room-by-Room Guide
Bedrooms: 2700K (warm, relaxing). Kitchen: 3000-3500K (warm but clear). Bathroom: 4000K (accurate colour rendering). Home office: 4000-5000K (alert, focused). Garage/workshop: 5000-6500K (maximum visibility).
The CRI Factor
Colour temperature tells you the tone. CRI (Colour Rendering Index) tells you the accuracy. Always buy bulbs with CRI 90+ for living spaces. Below 80 CRI, food looks unappetising and skin tones look sallow.
Smart Lighting Advantage
Tunable-white smart bulbs let you shift colour temperature throughout the day. Warm (2700K) in the evening supports melatonin production. Cool (5000K) in the morning helps you wake up. This is the single biggest quality-of-life upgrade in modern lighting.