Colour temperature is expressed in kelvin (K). The higher the colour temperature, the cooler the impression of the light:
2700K: extra warm white 3000K: warm white 3500K: neutral white 4000K: cool white 5000-5500K: daylight 6000K: cool daylight
Extra warm white creates a warm, inviting atmosphere (e.g. hotel, living room, and catering). Warm white can be used for a pleasant atmosphere (e.g. retail and office). Neutral cool white creates a more businesslike atmosphere, this color gives a sterile atmosphere. Low lighting levels are obtained in interior with warm white light. If a very high level of light is needed, neutral or cool white light is a good choice.
Dim to warm is a dimming technique that adjusts colour temperature as the light is dimmed: it shifts from warm white to extra warm white when fully dimmed. This technique has various names, such as Dimtone or Glowdim.
