If you have read our page about the meaning of color temperature, you understand that the Kelvin rating on a light bulb or fixture indicates the shade of white light that emits from that source. Just as sunlight transitions from orange shades in the morning and evening to blues during the middle of the day, artificial lights also emit a specific color temperature.
If you’ve ever been overwhelmed by the powerful light in an office building or grocery store, or found yourself relaxed by the yellow glow of a bedside lamp, then you know how broad the experience of various color temperatures can be. This isn’t saying that cooler or warmer color temperatures are better or worse than one another. Each color temperature has an application within an appropriate context, and good lighting design incorporates that into an overall plan of how to light an office building, a manufacturing facility, or a residential home. Knowing your environment is critical to choosing the right color temperature and can make all the difference in things such as employee performance or the consistency of your sleep cycles.
The Scale of Light Color Temperatures
Light color temperature is measured in degrees of Kelvin on a scale from 1,000 to 10,000, represented in numbers with a K after them, such as 3000K or 5500K. The scale is easy to follow. The lower the number on the Kelvin scale, the warmer and more yellow/orange the light will be. The higher the number is on the scale, the bluer the light will be.
Kelvin Color Chart
scale of color temperatures This scale shows the various color temperatures that are available in common light sources. They range from orange to blue, but remember that these are all white light. This graphic would indicate that the product is 5200K on the Kelvin scale of color temperature.
A good point of reference is that the sun at midday measure 5780 Kelvin. If you look at that color temperature on the scale of color temperatures, you’ll find the light is beginning to touch the edges of the bluish range of light. So, what you perceive to be white light actually has a bit of a blue as part of its spectrum. Typical household lamps use bulbs in the 2000-3000 Kelvin range, which often feels like white light with hints of yellow and orange as part of it. A candle registers at 1900K, so you can see how the glow of fire emits a warm, yellow/orange light. Keep in mind that these are all shades of white light.
What is Circadian Lighting
The natural color temperatures that we see throughout the day produced by the sun vary from warm to cool. The early and late sunlight is low on the color temperature scale, emitting a warm orange glow that has less intensity than at other times of the day. The sunlight that we see in the middle of the day is actually closer to being cool blue color temperature but appears to the eye as a clear white light at around 5780 Kelvin. The color temperature of a sunrise or sunset, on the other hand, is around 3200k.
Recent studies show that there are positive health effects when artificial lighting mimics the natural color temperatures of the sun throughout the day. This research serves as the basis for many of the color temperature recommendations we make in this post.
Warmer light is used in many living rooms and dining areas because we often spend our time there in the mornings and evenings. Warmer light tends to be more relaxing to the human eye and allows people to slow down and take it easy. We use cooler light in the workplace because we tend to be there most often during the middle of the day. Essentially, the core of what we want to achieve with color temperature is to match the natural rhythm of the sun. However, there are a few special cases that call for special light color temperatures.
