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Color Temperature Explained

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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)

Lighted Makeup Mirror

Lighted Makeup Mirror

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+.

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Benjamin is a writer for 1000Bulbs.com.

  • Jon

    Good write up. This issue has been PISSING ME OFF. While I didn’t know it until I had one, I only like 5000-6500k. Not only do I like the real raw impact that doesn’t change the look of things, but only do I even love it more when there is a blue hint, but I find it actually impacts my mood.

    I now HATE all the other light sources in my house.

    And now that LEDs are getting more popular, more and more of my fixture types are coming out in LED.

    But guess what? In an attempt to make them look like old lightbulbs that everyone is use to, these are usually ONLY OFFERED in 3000-4000k. And it’s KILLING ME.

    Our old lights are yellow because we didn’t know any better. The only real light is sunlight, and sunlight is NOT 3000k.

    Will everyone please please get over their inability to deal with change. The entire idea of taking a nice new clean technology like LED and using it to simulate an inferior technology is just blasphemy.

    • Benjamin Rorie

      Jon,

      You’re right. Color temperature is largely a matter of preference. There is not one color temperature that is perfect for everyone.

      And if you’re looking for high color temperature LEDs, we have several 5000K LED light bulbs on our website.

  • Jim

    In linear fluorescent fixtures that use pairs of tubes, we use 1 warm white and 1 cool white tube. It provides better color balance in the room, and seems brighter then using 2 of either type.

    • Benjamin Rorie

      Jim,

      That’s a really cool idea, but why not just use a 3500K fluorescent (halfway in between warm and cool).

  • Becca

    Am looking for something that is highly visible when walking my dogs at night. Is this something I would be able to adapt to this use. Am desprate and tired of looking at promising web sites only to find one or two unuseable or cheap items. Help!

    • Benjamin Rorie

      Hi Becca,

      I’m not sure what you’re looking for. Are you looking for a light for the exterior of you home, or a flashlight or battery-operated lantern for taking with you on your walks?

  • Anders Hoveland

    Fluorescent and LED bulbs do not actually have a true “color temperature” because they do not generate their light from incandescence. Instead, something known as “correlated color temperature” is used to try to describe the distribution of the different light frequencies in their output. Correlated color temperature is not a perfect measure light color. In fact, it is hypothetically possible for two different light sources to be completely different colors but have the same correlated color temperature. But in general, the higher the color temperature, the more blueish the light source will be. Again, there is much more to quality of light than than just color temperature.

  • http://none edgar malonjao

    is there a statement or rule that street or road lights must be 3000K (warm/yellow) for better visibility during rainy days/nights?

    • Jordan Loa

      We appreciate you reaching out to us, Edgar!

      However, there’s not a rule or a statement that we’re aware of concerning street or road lights must be 3000K for better visibility during rainy days/nights.

      Thanks!

  • Numberwoman

    We have decided to change over to LED at home, and after doing lots of investigation, I decided I wanted the coolest white available, 6500K with the blue-ish tinge. Unfortunately, I have found there is no consistency and that different suppliers are classifying the bulbs differently. The ones I ordered were referred to as ‘cool white’ but when they arrived, they were only 4000k, and this is what another supplier refers to as ‘natural light’ and yet another supplier refers to as ‘daylight’. The supplier I ordered from, has their 6500k referred to as ‘daylight’. Why such confusion? Is there no ‘standard’ terminology for the classifications?

    • Jordan Loa

      Numberwoman,

      We apologize for the confusion, and hope we can clear it up for you.

      The term “cool white” does indeed refer to 4000 to 4100K color temperatures, while 6500K typically refers to “stark white” or “daylight”. As you now know, different suppliers have different names for each of the color temperatures. However, the best lamp for clarity is a 5000K lamp, as it has the right amount of blue. Some people don’t like the 6500K lamps because of its very blue nature. Unfortunately, as you now know, there really isn’t a standard terminology across the board. What some people call cool white, some may call “natural light.”

      As a general rule of thumb, the temperatures 2400-3000K refer to warm white. 3500K is referred to as “neutral”, while 5000-6500K is referred to as “stark white.”

      Hope this helps!

  • Mike

    Is there any way to put a lense or film to make a 4000k a little less blue

    • http://www.1000bulbs.com Jessica Banke

      Hi, Mike! The answer to your question depends on your bulb and the fixture. Some bulbs, like fluorescent tubes, often have lenses/covers made for the fixtures they are installed in. While lenses don’t typically make lights any less “blue,” some options can at least reduce the intensity of the light, which might help. Definitely let us know if you have further questions!

  • npmcgowan

    I am in the midst of replacing all of the old lighting in my house with 5000k lighting. Especially in Cleveland, where in the winters it is dark when you go out and dark when you get home, I noticed that my mood was better with the 5000k bulbs over the incandescent. It also made my home feel cleaner. Now that I have done it, I actually have several friends who are making the switch as well. I highly recommend making a “whole room switch” if you are going to try it. Do not try a “one bulb at a time” approach, as it will really not feel right.

  • Frankie

    The reason street lights are yellow is due to money rather than law. Sodium vapor lights are cheap, durable, and were very efficient by 20th century standards.

  • Shelley Ventura

    Does anyone have ideas on how to change the
    ‘warmth’ of existing LED fixtures. A year or so ago, my company outgrew its
    space so we built out a 3000 sq ft area of warehouse connected to the existing
    office space. One of the owners decided to go with LEDs, and didn’t investigate
    the color aspect of the lights. It’s a very noticeable difference between the
    warm white fluorescents in the original office – which also benefits from some
    natural light – and the harsh white light of the new area. We’ve dimmed the
    room, but naturally that has no impact on the color. The employees hate the
    lighting in the new area, but the money’s spent and the fixtures are installed.
    Are there any films or filters that be installed over the lights to soften or
    warm the color? We will not be spending the money to change out all the existing fluorescents in the original 75000 sq ft office.

    • Will Parsons

      There are filters and gels which can change the colour or colour temperature of the light, the issue will be finding a filter that fits your fixtures. Most of these gels are designed for stage and studio lights such as Source Four lamps, and not for standard office lighting fixtures. My suggestion would be to call our customer service department, as they may be able to help you find filters if they know what type of fixtures are being used.

      Will Parsons
      Sr. Copywriter
      1000Bulbs.com
      2140 Merritt Dr. | Garland, TX 75041
      800-624-4488 Ext. 279