Color temperature is one of the most elemental factors of light to understand, affecting not only how our home looks, but also how productive we feel and how we sleep each night!
We hope this quick overview can serve as your general guide to color temperature and beyond!
What is color temperature?
So, what exactly is color temperature?
Color temperature is a measure used to describe a light source's visual appearance and whiteness.
Just like natural sunlight appears in many shades throughout one day, "artificial" lighting or light bulbs also come in many shades of white. These are a light's color temperatures, represented as degrees Kelvin (˚K).
In terms of light bulbs, most fall anywhere between 2700K and 6500K.
The lower the Kelvin temperature, the "warmer" or more red the light, the higher the Kelvin temperature, the "cooler" or more white and blue the light.
Of the above 2700K-6500K range, 2700K represents a warmer light, and 6500K a bright white light.
Standard color temperatures in the home
2700-3000˚K (Warm White)
3800-4500˚K (Natural White)
5000-6000˚K (Cool White)
Color temperature in relation to the light spectrum
So, we mentioned that 2700K is "warmer" than 6500K. Why is that, and why would you want a warmer light vs. a cooler light?
This is where it helps to have some background on the light spectrum itself. Visible light - which exists only as a narrow sliver on the electromagnetic spectrum - is comprised of all the colors of the rainbow: Pass white light through a prism, and you'll see it separated into its constituent bands of Red, Orange, Yellow, Green, Blue, and Violet.
Each of these colors of visible light has a wavelength and energy. For example, red light has the longest, slowest moving wavelength, while blue light has shorter, faster wavelengths.
Of course, sunlight is always a full spectrum of light. But, as we just discovered, its color temperature will depend on the time of day, and whether the visible light spectrum skews more towards the red color wavelengths of light or more towards the opposite blue light wavelengths.
So, if you've already guessed, sunlight at dawn and dusk is warmer in color temperature,(more red light wavelengths), and has an approximate color temperature anywhere from 2000K-3000K.
At noon, when the sun is directly overhead, sunlight appears bluer (from an increased presence of blue light wavelengths), and can have a color temperature anywhere from 5000K-6500K.
Color temperature and its effect on sleep, productivity, and mood.
So you know that a light's color temperature determines how a light source appears: if a light is warm and red appearing, we know its a warmer color temperature in the 2000K - 3000K range, and the corresponding light spectrum will have more red light wavelengths than blue light wavelengths. The opposite is true for cooler color temperatures of light in the 4000K-6000K range - which will have progressively larger quantities of blue light wavelengths in their light spectrums.
But so far, we've only been talking about appearances: how does a light's color temperature affect us in our day-to-day lives?
Let's explore how each color temperature affects our mood, productivity, and sleeping patterns.
Cooler color temperatures promote energy + alertness, while warmer color temperatures promote feelings of rest + coziness.
Let's start with cooler color temperatures of light, as the increased presence of higher energy blue light wavelengths is precisely what can increase alertness.
As a quick summary: our eyes are inherently sensitive to blue light wavelengths, which tells the brain and our body that we better wake up and suppress any melatonin (the hormone responsible for sleepiness) that may be circulating. Learn more about how blue light (and light in general) affects sleep.
This blue light is why we're told to keep our lights warm in color temperature in the evening; the blue light in the cooler lights can prevent you from falling asleep at night!
If you want to dive deep into the whys and hows of lighting and biology, you can learn everything about light and health in this article.
So, with the above in mind, let's explore some viable color temperatures for each room in your home!
The best color temperatures for each room of your home
Each color temperature has an aesthetic and energetic effect on a room. When deciding the best color temperature for each room in your home, most recommendations result from the mood or ambiance you'd like to create.
Remember: cooler color temperatures promote energy + alertness, while warmer color temperatures promote feelings of rest + coziness.
These general effects form the basis of all recommendations. Therefore, keep in mind your intended room application and use. For example, using your living room as an office space would warrant a different color temperature suggestion than using your living room as a bedroom!
With that in mind, here are some color temperature ranges that work well:
We can probably all agree a softer, warmer light is a better choice in the bedroom than very white and stimulating light.
Limiting exposure to blue, bright light (in the form of screens and light bulbs) is crucial at night in preparation for bedtime. If you need help winding down in the evening, try neodymium glass light bulbs, which will have a redder, more soothing spectrum of light.
Some of our favorite bulbs to use in the bedroom:
For overhead recessed lighting: Chromalux® R25 60W flood bulb
Living Room: 3800-4500K
Natural white is a typical choice here. It's a soft and neutral range that works well in "neutral" spaces like living rooms.
Some of our favorite bulbs to use in the living room:
For overhead recessed lighting: Chromalux® full spectrum R30 72W enhanced
Similar to our living room recommendation, yet a bit warmer. We find this range to be both soothing and natural.
Some of our favorite bulbs to use in the bathroom:
For overhead recessed lighting: Chromalux® full spectrum PAR lamps
For bathroom vanities: G25 Clear - 40W Chromalux® Full Spectrum Vanity Bulb
A higher natural white range works well here. 4000K is more neutral, while 5000K will give off a whiter, brighter, and "cleaner" effect.
Some of our favorite bulbs to use in the kitchen:
Same color temperature; different light: other qualitative factors to look out for in lighting
Two light bulbs can have the same color temperature while varying tremendously in appearance.
Now that you have a base guideline on color temperature let's explore a few other descriptive elements of light bulbs of which you should be aware.
Lumens: The brightness of the light emitted by a bulb. While wattage describes a bulb's energy draw, lumen count better describes how much light a bulb emits or, simply put: how bright the bulb is.
CRI (color rendering index): This measure is most indicative of a light's quality. CRI is a measure on a scale of 1 to 100 of how accurately a light source shows colors compared to natural sunlight (with a CRI rating of 100).
A light bulb with a CRI above 90 is considered good, and above 95, excellent for color vibrancy and a more natural-looking interior. Stay away from CRI ratings below 85, which have a dulling effect on surroundings.
Color temperature is a subjective measure best chosen according to your intended application and aesthetic preferences, but don't let the search end there. Choose high CRI bulbs in your intended color temperature range for the best lighting experience.
Remember, while two bulbs with a 4200K color temperature give off a similar color of light, one can be brighter yet duller than the other if it has a higher lumen count yet lower CRI.
💡Thanks for reading!
A little about us: Our parent company, Lumiram, is the original maker of full spectrum neodymium glass light bulbs. We attribute much of what we know about lighting in relation to health and beauty to them and their flagship brand, Chromalux®.
Neodymium is a magnificent color-enhancing and purifying element that is compounded into all Chromalux® full spectrum light bulbs. We highly suggest you start there if you need color definition, purity, and natural lighting.
Regardless of color temperature.
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