Anyone who has ever shopped for an LED light bulb or purchased LED strip light has probably heard terms like cool white, warm white or natural white. If you’ve really done your research you might have noticed that these terms are also attached to a scale of numbers called the Kelvin Color Temperature. That scale ranges from 1,700 K to 27,000 K and looks a little something like the chart below. So what does the chart below mean and how does that number associate with the set of LED light bulbs you’re looking to purchase? This post will give insight on what color temperature is, and how to apply it to your lighting.

The Origin of the Kelvin Color Temperature Scale (If you want to geek out)

Up until the invention of LED lighting, temperature was directly related to the type of color a light source would produce. In fact every man made light source besides LED lighting required the production of heat in order to make light. If you remember from your high school science class Kelvin is a unit measure of temperature (reminder: it was usually attached to how hot the sun was or some distant star). A Kelvin color temperature scale works something like this; if you were to stand next to and look at a torch flame you could feel how very hot it is and see that it gives off a very intense blue light. In contrast if you were to stand next to and look at a candle it has very little heat and produces a less intense yellow light. So that’s why when you see a light bulb with a color temperature of 7,000K it will have a blue hue to it compared to a 2,700K light bulb that has an orange hue to it. Helpful hint: Cool white and warm white do not directly relate to actual Kelvin numbering scale. “Cool” refers to the icy bluish hue that a higher color temperature produces and “warm” refers to the candle-light-yellow hue a lower color temperature produces.

Applications of color temperature

Color temperature is really more a preference of color than it is a way to measure the brightness or quality of the light. However, there are a few characteristics certain color temperatures have that may impact your preference and choice. Let’s go over a few questions that will help you choose a color temperature and determine what your preference is: where is the light going, what type of mood do you want for that space, and how do you react to certain color temperatures?

Where is the light going?

Are you looking to place this light in a living room, hallway, kitchen, or bedroom? Where you are placing the lightbulb may determine what color temperature you choose. A lower color temperature or warmer light (2,700K- 3,000K) is less intense to our eyes and often works well in a living rooms, family rooms, or bedrooms where we want to promote relaxation. A higher color temperature or cooler light (5,500K-6,000K) is more intense and often works better in areas that we are working or carrying out some type of task, like chopping food in a kitchen or doing exciting accounting work in an office. If you’re placing a light outdoors, the more intense cool white light may offend neighbors and confuse wildlife. On the other hand you may also more easily get the attention of an onlooker with a cooler white.

What type of mood do you want?

Because warm whites carry a lower frequency than cool whites and are therefore less intense to our eyes you can often set a cozy more relaxing mood with a warm white light. If you’re needing to keep a more productive mood in the area you are lighting a cool white which has a higher frequency and is more intense to our eyes might give an added benefit.

How do you react to a certain color temperature?

Not everyone responds the same to a certain color temperature or enjoys the mood and feeling it helps to promote. I personally don’t like the look of a real warm light (2,700K) because it makes me feel tired and slow. I prefer a natural or even cooler color temperature (4,800K-6,000K) because I feel more energetic and awake. Others feel that cool and natural lights are too bright and hurt their eyes. You’ll have to find out what your response is to different color temperatures and determine which you prefer.

Other measurements of light

If you’re trying to determine what light will work best for your situation, color temperature is not the only measurement you’ll want to consider. Delivered lumens, wattage, and color rendering index are other measures you’ll want to look into to determine the best light for your needs. Here is a brief description of each measurement and its function. Lumens: are the amount of visible light a source can produce. It will typically help you to know how bright a bulb will be. In this case, higher is brighter. Helpful Tip: Although many feel cool white lights are brighter than warm white lights, it is more a perception than a reality. Cool white has a higher wavelength frequency and therefore is more intense to our eyes making it appear brighter. However, If you compare a warm and cool white light that delivers the same amount of lumens they will both be as bright as the other, but produce different colors. Wattage: is the amount watts, or units of power the light requires. This will help you to know how much energy you are consuming with the light you purchased. The higher the wattage used the more energy you consume. Color Rendering Index (CRI): is a measure of quality and helps to reveal a light sources ability to show colors as they truly are. This measurement is different than color temperature because instead of determining what color the light will produce the CRI will determine how well colors will look under that light. Higher CRI ratings will produce better quality light.

Need help deciding what light to buy?

If you have a lighting project you’re working on or have questions about lighting in general, we’d love to help. Leave us a comment, call, or email and we’ll get you what you need. Birddog has been in the lighting industry for over 10 years and has made it our focus to help you accomplish any lighting project you desire. Whether you are changing out a light bulb or working on a unique lighting masterpiece our lighting professionals can help you along the way.