When meeting with customers to look at their lighting, I occasionally hear the phrase, “It is too bright over there.” When I hear this, I often follow up with the question, “Can you explain what you mean by ‘too bright’? Do you feel you have too much light or is the light ‘too’ white?”

The answers always vary. Sometimes a customer is referring to the quantity of light that is needed or not needed, other times a light source is causing too much glare, and many times, the customer just doesn’t like the color temperature of the light.

 

How Does Traditional Color Temperature Translate for LED?

Color temperature in lighting refers to the tone of “white” light that is emitted from a light source.

An easy way to think about it is to think of all the shades of white a T-shirt may go through in its life. Wash it with your dark blues and the white T-shirt still looks white on its own, but put it up to a new shirt and it may look slightly blue. Wear a T-shirt too long, and when you set it next to a new shirt, you realize the old one is now yellow. White light also looks very different when two different sources with two different color temperatures are put side by side.

In order to differentiate the various hues of white, artificial light sources are labeled with either a color temperature (incandescent and tungsten halogen) or a correlated color temperature (CCT) (nearly everything else). Both color temperature and CCT are measured in degrees Kelvin, derived from “blackbody radiation”.*

Simply put, as an idealized blackbody absorbs radiation, it glows different colors. At a temperature of 2000K, it is a very orange-yellow color. As the temperature increases, the color shifts to yellow, yellowish white, white and then a bluish white.

So in the lighting world, the color of white has traditionally been classified as warm white or cool white, depending on its CCT. When our lighting sources were more limited and LED was not a commercially available item, incandescent, halogen, and fluorescent with a CCT of 2700K or 3000K were known as “warm white”. Fluorescents with a CCT of 3500K were called “neutral” and any source with a CCT of 4100K and above were considered “cool white”.

 

//play.vidyard.com/XxtWKbuI1Vml2-7JtvKKqw.js?v=3.1.1&type=inline

 

LEDs Have Impacted CCT

LEDs have changed that. When LEDs first became commercially viable in “white”, they were least expensive in the bluer spectrum, so nearly all of the early “white” light sources leaned toward a CCT of 6000K and above. Because of that, we now see manufacturers calling 5000K neutral, and I’ve even seen some call 4000K “warm white”.

That said, the most important tip I can give to LED buyers is to ask what the correlated color temperature of a lamp or fixture is before purchasing it, not whether the color temperature is “warm” or “cool”.

Another very important note is that correlated color temperatures have a chromaticity range. Without going into scientific detail, to an installer and end user, that means that not all 2700K CCT lamps will look the same. So to avoid any issues, it is best not to mix and match manufacturers unless you have tested their products with each other.

 

Why is Understanding CCT Important?

The reason CCT is important is because of the way light makes a space feel.

Candlelight ranges from 1500–2000K, and to most people it is romantic-feeling. Thus restaurants, hotels, and homeowners who want a cozy feel may want to look toward color temperatures that are 2400–2700K. Transitional spaces moving from cozy to a more productive space (like hallways) may opt for color temperatures in the 3000–3500K range.

Warm CCTs also draw out the warm colors in furniture, art and other objects in the space. So designers will usually recommend 2700–3000K if you want to highlight the reds and yellows in the wood grain of your flooring.

On the other hand, I am seeing a lot of commercial and industrial facilities trending toward 4000–5000K sources because the light more closely matches daylight, and they feel it makes a space “feel” more productive and business-focused.

The other advantage to cooler light is that often people perceive it as “brighter” or producing more light than a source with a warmer color temperature. Because of this increase in perceived light, shifting to cooler color temperatures may also have an energy-saving effect for some businesses, as they can actually use less light than they could with warmer CCT sources.

 

Understand Your Objective for Lighting in Every Environment

There are pros and cons to both warm and cool color temperatures. The key is understanding the environment you are putting the lights into.

Warm colors can be perceived as “not bright enough” if they are used in an area where people want crisp white light to work under. In areas where naturally cool-colored daylight enters from windows and skylights, warm colors tend to look more yellow or pink, so people may think the lights aren’t working properly.

The potential downside of using cool colors is that many people perceive it to be “institutional” or “sterile”. People may complain that their lighting is “too bright” if you change from a warm color to a cool color, even if the measured light output remains the same or decreases slightly.

Evaluating the needs of your environment is key to picking the right color temperature.

Make sure you tell your supplier what type of environment or what type of ambience you are looking to create in a space. Also, if you plan on shifting from one light source to another (fluorescent to LED), or changing the CCT, my recommendation would be to finish entire rooms at the same time. Just like the analogy with the T-shirt, if people don’t see two different CCT light sources near each other, it is harder to notice a difference.

 

Authors note: * For the purpose of readability CCT and color temperature is used interchangeably throughout this article to mean the relative Kelvin color of a light source, regardless if the source has a true color temperature or a CCT.
We carry thousands of LED and lighting products for commercial, industrial and residential projects. Your Border States account manager can help you choose the right products for the job, help you find alternatives and teach you about LED and lighting. Contact your account manager today at 800.342.3791.

Not a customer of Border States? Register online, give us a call at 800.342.3791, visit your nearest branch, or fill out our online contact form to learn more about Border States’ wide selection of lighting solutions, from some of the most respected experts in the field.

If you Need Help With Lighting

Border States is also here to help if you have any questions about lighting technology, controls or best practices for LED lighting projects. Schedule a free consultation to learn more about lighting audits or how controls could save your facility some cash.

6 Comments
  1. Janice Hall 7 months ago

    Great article. I’m having a hard time with a new barn style lamp. I liked it because of the vintage exposed bulb, but at 2000K, 60 watts, it blinds me, although the yellow orange glow is warm and wonderful. Should I go to a 2700K? Lower wattage in 2000K?

  2. Tamara Leher 7 months ago

    Good question! The intensity of light output is still driven by the input wattage, similar to how a 60W incandescent bulb emits more light (lumens) than a 40W bulb. Moving to a lower wattage lamp (either a 40W or a 25W equal) will cut back the intensity of the light and make it easier to see the decorative filament inside. For this application, don’t worry too much about color temperatures below 3000K; any source between 2000K and 2700K will still emit warm, yellow tones similar to incandescent. Also, if these will be on a dimmer, you might also want to check out products that dim to a warmer (lower) color temperature. As the light output is lowered, they also become more amber-colored resulting in a warm glow similar to incandescent lighting.

    Kyle Christensen, LC, IES Associate
    Construction Market Specialist | Lighting, Electric Heat, Solar/Wind

  3. Ron 4 months ago

    Hi,
    Can you advice the correct light for meat processing plant?

    Thank you
    Ron Albeg
    Preen Pets Corp
    ronpreen@yahoo.com
    USA

  4. Border States 3 months ago

    Hi Ron,

    For meat-processing facilities, you would want a warmer color temperature (3,000-4,000K) and a CRI of at least 80. Look for fixtures with high R9 (red) and R12 (blue) rendering. Also, for your application, we’d recommend that the fixture/retrofit solution be NSF-listed and IP67 wash-down rated.

    Unfortunately, we don’t have any locations near you in PA, but you can find a reputable lighting professional through your local IES chapter (illuminating engineering society) or through the NCQLP website (National Council for Qualified Lighting Professionals).

    Thank you!

    Team Border States

  5. GS 3 months ago

    I need a recommendation for Flat panel LEDs to replace Fluorescents in a drop ceiling in a basement art studio. I am a jeweler who works with gold and silver, highly reflective but I also work with non-traditional materials such as polymer clay so color and texture are part of what I fabricate. Noteworthy is that I work with very small dimensions – millimeters and things have to fit well. I also solder in this space and need to be able to dim lights at times to be able to see the color of my metal as it is heating. My space is divided into work stations to perform specific tasks such as a soldering station, a fabricating station, a buffing station, etc. I thought 5000K would be the best color temp. but it was recommended to me that I use 4100K instead with the notion that 5000K would be too white/blue. Your thoughts?

  6. Border States 3 months ago

    Hello,

    These are some unique lighting challenges, indeed.

    First, to answer your question about color temperature, it’s a matter of personal preference and what feels most comfortable for you to work under for long periods of time. That said, I did an LED retrofit for a kitchenware manufacturer one time who swore by 5,000K in the quality inspection areas and 4,000K everywhere else. The plant manager said his employees had an easier time seeing imperfections in the metal under 5,000K lighting. Studies have also shown that American school children are more alert and score better on exams under 5,000K versus 3,000K, so there may be some credence to this assertion.

    Next, you are performing a wide range of tasks in this space and LED flat panels may not be the most appropriate solution for every task. Working on tiny jewelry requires a large amount of light at the task plane, depending on the reflectivity of the surfaces in the room and the age of your eyes (older eyes need more light due to lens yellowing, cataracts and muscular atrophy over time). LED panels may work for general illumination, but dimmable task lighting (table lamps, strip lights, undercabinet lights) may be better solutions for each workstation/task. Look for fixtures and dimmers that dim down to 1 percent or lower; studies have shown that LED products dimmed to 10 percent power still appear to be at 32 percent perceived brightness. Also, look for fixtures with a superior diffuser over the LEDs. If the intense LED diodes are visible, or poorly diffused by a lens, it could cause glare/sparkle on your task, leading to visual discomfort. I would definitely recommend doing a mock up over one workstation and perhaps a trial installation period before committing to the full project.

    Lastly, the best thing to do is to have a professional lighting specialist visit the space and generate a lighting design based upon Illuminating Engineering Society recommendations. Border States has lighting specialists based in Phoenix, Nashville, Charlotte, Minneapolis, Billings, Fargo and W. Columbia, SC. If you live outside these areas, you can find a lighting professional through your local IES chapter (ies.org) or through the National Council for Qualified Lighting Professionals (ncqlp.org).

    Good luck!

    Team Border States

Leave a reply

Your email address will not be published. Required fields are marked *

*

Log in with your credentials

Forgot your details?