Should I Choose 4000K LED Lights? An In-Depth Look

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When shopping for LED bulbs, you'll come across "warm white" or "soft white" bulbs, which typically have a color temperature rating of 2700K or 3000K. For most residential installations, especially bedrooms and living room areas, these color temperatures will work well.

Then, there's a jumble of names ranging from "neutral white," "bright white," "daylight" and "cool white." You might be tempted to think they're all the same, or close enough. In reality, these names can refer to a wide range of color temperature options, including 4000K, 5000K and 6500K. If you want to make an educated decision when purchasing LED bulbs, you'll want to get a bit more technical, and know exactly which color you're getting!

In this article, we'll go over the 4000K color temperature option, and help you determine if that is the best color choice for you.

What Does 4000K Look Like?

4000K is an often overlooked color temperature, as it falls right in between "warm white" (2700K/3000K) and "daylight white" (5000K/6500K) color options.

As one would expect, is most definitely on the "cool" side when compared to typical warm white lighting options, but is also on the "warm" side when compared to daylight color temperatures.

You are most likely to encounter 4000K color temperatures in retail and office spaces. It is also the color temperature of direct sunlight during morning or afternoon hours.

This makes 4000K a popular choice for customers looking for a bit more clarity and crispness in their light, but also don't want something too blue or stark.

(Of course, one of the best ways to answer this question is to see a 4000K light source in person. For this reason, Waveform Lighting offers a 30-day free returns policy in case it turns out 4000K doesn't work for you.)

Is 4000K Similar to Natural Daylight?

Comparing LED bulbs to natural daylight a bit tricky, because natural daylight itself is always changing, depending on the weather, time of day, season and latitude. The reason for this, is that the sun itself has a constant color temperature of approximately 5800K, but depending on how the color of the sky, the color temperature of natural daylight can change significantly.

In general, the more red/orange the sky is (morning or afternoon light), the lower the color temperature, and the more blue the sky is (mid-day daylight, or windows facing away from the sun), the higher the color temperature.

As such, you will find that the color appearance of a 4000K LED bulb is similar to natural sunlight during morning or afternoon hours. During mid-day hours, direct sunlight will have a color temperature over 5000K, and daylight (including the entire blue sky) will have a color temperature closer to 6500K.

Finally, just because an LED bulb emits a color that looks like natural daylight, does not mean that it has the same light spectrum as natural daylight. If you are looking for an LED light to perform color-critical tasks, or are looking for full spectrum lighting for a health-related application, you will need to look at the LED bulb's color rendering index (CRI) value to get a better sense of the spectral similarity. A high CRI value of 95 or higher typically ensures that the light spectrum does indeed replicate a natural light spectrum.

Will 4000K Appear Too Blue? Will 4000K Appear Too Yellow?

The human vision system has an impressive way to adapt to ambient lighting conditions. What this means is that depending on what your eyes have adapted to, its appearance can differ.

Let's say you're considering 4000K for your home kitchen area. During evening hours, if you walk from your 3000K living room lighting into the 4000K kitchen, things will definitely appear whiter and crisper. Will it appear too blue? We don't think so - it is definitely a more intense, white color, but not a harsh, blue color.

Now, let's consider what happens during daylight hours. Your 3000K lamps are turned off, and natural daylight floods your living room. Your kitchen doesn't have many windows, though, so you use the 4000K lamps during the day.

When you walk into your kitchen, you'll definitely feel like the lighting is a bit more yellow. That's because your eyes have adapted to natural daylight, which has a very high color temperature (6500K or higher).


You might notice this when walking into retail stores. During bright daylight, when you walk into the store, you might notice that the lighting is a bit on the yellow side. Then, go to the same store at night, and you'll feel that the lighting is a crisp, white color. Unless the store has some color-changing lighting system, chances are that the same 4000K light color appears different because your eyes have adapted to different lighting conditions.

Our conclusion is that 4000K may appear too yellow compared to natural daylight, but unlikely to appear too blue compared to incandescent or warm-white lighting, although this is ultimately a personal preference question.

When our eyes are adapted to, or are expecting a true natural daylight color at 6500K, the color temperature difference is a large 2500K difference.

When our eyes are used to a warm-white, residential color temperature of 3000K, the jump to 4000K represents a smaller 1000K difference.

But because it is a mid-point color temperature, the differences are not very stark either way. Since it is neither too far from residential warm-white colors nor natural daylight white, 4000K can be a very effective color temperature choice.

Where Should I Use 4000K Bulbs?

4000K LED lights can be used very effectively in retail, office and certain areas in a residential application.

For retail and office applications, 4000K can provide a lively and clean look, without appearing too blue or sterile, especially during evening hours. Compared to warm-white color temperatures, 4000K provides a higher level of color clarity that may be crucial or beneficial in retail and commercial applications.

In residential applications, 4000K LED lamps would be beneficial for areas where additional color clarity is desired. Kitchen and food prep areas as well as bathroom and vanity areas may be potential areas where 4000K can be helpful. Do be mindful of color differences between other areas of the home that have warm-white lighting installed, and perhaps choosing 3000K over 2700K may be helpful in reducing the color difference.

Finally, for industrial or color-critical applications, we recommend 5000K (D50) or 6500K (D65) options instead. That is because 4000K provides a yellower color balance compared to natural daylight color temperatures.

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