Color Temperature Explained
Every light source has a distinct character, from the warm, dim glow of a candle to the blue, bright beam of a street light. Brightness, measured in lumens, is one part of that character; the other part is color temperature. Measured in degrees Kelvin, color temperature is not the ambient hot/cold temperature of our surroundings. In fact, the Kelvin scale goes backwards: The higher the color temperature, the cooler light gets, and the lower the color temperature, the warmer light gets.
Warm Color Temperatures (2000K to 3500K)
Most homes look best in warm-toned light. This is for several reasons, but the first one is a home's color scheme. People tend to decorate homes in warm earth tones—reds, oranges, and yellows—which warm light enhances. In addition, people tend to look better in warm light. If your grandmother had a lighting makeup mirror with adjustments based on "office," "home," and "evening" lighting, you may remember that you looked a lot better in "home" and "evening" modes than "office" mode. That's because (you guessed it!) those modes had lower color temperatures than "office" mode.
Cool Color Temperatures (4000K to 4500K)
While warm color temperatures are the residential standard, some people prefer higher or "cooler" color temperatures. Because of their neutral tone, it's common to see color temperatures of 4000K or higher used as task lighting in offices. Moreover, people often perceive higher color temperatures to be brighter than warm temperatures, while others feel cooler light looks "cleaner." Finally, higher color temperatures can enhance homes with cooler color schemes, especially those with a lot of blues and whites.
Full Spectrum Color Temperatures (5000K to 6500K)
Less common are very high color temperatures, often referred to as "full spectrum" or "daylight." Color temperatures of 5000K to 6500K approximate the color of light outdoors on a bright, sunny day. The cast of the light can be a very pronounced blue and can seem harsh to some people. It's unlikely to see color temperatures of this range in homes, though there is a trend of installing "full spectrum" bulbs in offices as they are sometimes associated with higher productivity.
Making a Decision
There's nothing that can sour your opinion of CFL or LED lighting like buying a 4000K or 5000K bulb when you meant to buy a 2700K bulb, or vice-versa. When you buy a new, energy efficient bulb, keep your application and color scheme in mind and make sure to buy the bulb with a color temperature to match.
So do you prefer warm or cool color temperatures in your home? Have you ever mistakenly bought a bulb of the wrong color temperature? Share your thoughts and experiences in the comments section below or contact us on Facebook, Twitter, or Google+.