Colour temperature & CRI: clear at last

2700K, 3000K, CRI 90… yet these numbers shape the mood of your room far more than the form of the light itself. Here is what they mean, in plain terms.

Colour temperature: Kelvin, not watts

Colour temperature is measured in Kelvin (K). The lower the number, the warmer and more golden the light; the higher it is, the cooler and bluer it becomes.

• 2700 K — very warm white: evening light, golden and enveloping. Ideal for the living room and bedroom.
• 3000 K — warm white: inviting but slightly brighter. Perfect for a dining room or entrance hall.
• 4000 K — neutral white: crisp, functional light. Best kept for the kitchen, the bathroom or a worktop.
• 5000–6500 K — cool white: clinical ‘daylight’. Avoid it in living spaces; useful in a workshop or garage.

Our stance at Lumsky: warm white (2700–3000 K) in every room you live in. It is what makes a home feel welcoming in the evening, rather than lit like a car park.

CRI: colour as it really is

The CRI (Colour Rendering Index), or Ra, scores from 0 to 100 how faithfully a lamp renders colours. Under a low-CRI lamp, your beige sofa turns grey and your complexion looks dull.

• CRI < 80: dull colours, best avoided at home.
• CRI 80–89: good, enough for most rooms.
• CRI ≥ 90: excellent — materials, wood and skin look true and alive.

The right instinct in one sentence

For a living space: aim for 2700–3000 K and a CRI ≥ 80. It is the combination that warms the atmosphere and keeps colours true. The rest is simply a matter of lighting style.