Color of Light – How does the Industry rate color appearance?

A. The color of a light source (measured in degrees Kelvin) tells you the degree of warmness or coolness of a light source. As degrees Kelvin increase, the color of the light source becomes whiter or bluer (cooler) compared to lower temperatures that appear warm.

A typical household incandescent light bulb has a color rating of approx.. 2700-2800K which is rather warm. A Cool White fluorescent on the other hand has a rating of approx. 4,100K and appears cooler or bluer.

It is a matter of preference. If you are replacing standard incandescent lamps you would most likely choose a warm color (2700). If replacing halogen, a 3000K LED lamp would be similar. If replacing Cool White fluorescent, you would choose a 4,000-4100K LED product.

This is of course, if you want the same basic color look. Some people ask for daylight color……….you should know that natural daylight changes dramatically during the day from warm in the AM to blue/white mid-day, back to warm in the late day.

Those that prefer a daylight source typically choose a light source of approx. 5000K which simulates noon daylight on a clear, cloudless day. Also note that 5000K sources are good when doing color matching since it does not alter the color of things by not being biased toward warm vs. cool.