Colour Temperature

Colour temperature describes the warm, neutral or cool appearance of white light.

Colour temperature is a kelvin value for the appearance of white light. It does not describe brightness, colour rendering quality or glare.

Technical meaning

  • Colour temperature, often written as CCT, describes whether white light appears warm, neutral or cool on a kelvin scale.
  • Lower kelvin values usually look warmer and more amber, while higher values usually look cooler and bluer.

Calculation use

  • Colour temperature helps a lighting estimate record the intended visual appearance beside the lumen, lux and beam assumptions.
  • CCT can guide room-by-room selection notes, but it does not increase the calculated light output or replace a lux target.

Not the same as

  • Colour temperature is not brightness. A 3000 K and 4000 K lamp can have the same lumen output.
  • Colour temperature is not colour rendering quality. CRI or other rendering measures must be read separately.

Australian context

  • Australian lighting notes commonly separate warm residential ambience, neutral work areas and cooler utility tasks while still checking glare, output and rendering separately.

Examples

ExampleValuePlanning note
Warm white2700-3000 KOften used for relaxed residential ambience when the required output is checked separately.
Neutral white3500-4000 KCommon for kitchens, offices and general task areas where appearance should feel clean without relying on CCT for brightness.
Cool white5000 K+Can suit utility or inspection tasks, but glare control and colour rendering still need separate attention.

Calculation limits and records

  • This site treats CCT as an appearance descriptor. It does not claim that a kelvin value alone makes a space brighter, safer or better rendered.

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