Color temperature

Color temperature describes which way white light leans and is measured in kelvin (K). The naming feels backwards at first: low kelvin values mean warm, yellow-orange light, while high values mean cool, bluish light. A candle flame, a tungsten bulb, midday sun and an overcast sky all sit at different points on that scale.

How it shapes a space

Homes tend to use warm white in living and sleeping areas, where people want to unwind. Kitchen worktops, desks and offices usually get neutral or cool white, which helps with focus and makes colors easier to judge. Mixing color temperatures carelessly in one room leaves a patchy result, with one corner of the ceiling looking yellow and the next looking blue. In lighting design this value deserves as much thought as the choice of fitting.

Color temperature in architectural rendering

Render engines let you set a kelvin value for every light. For a believable scene, the sun, the sky and the artificial lights keep their natural tones, and the camera’s white balance is set to the dominant source. In dusk exteriors, the contrast between the cool blue sky and warm light spilling from the windows gives the image depth and the sense that people actually live there. Our article on night exterior rendering covers that setup in more detail.