Advantages and disadvantages of color temps?

3000K, 4000K, 5000K and 6500K are common colors. But why pick one over the other?

I know that certain colors look more like daylight. If that was ideal only one color was sold I guess.
What are the advantages of each color?

Is it for example so that some colors look brighter at the same lumen because that’s how our eyes work?
Do some colors reflect less?
Are our eyes able to see more detail at certain temps?
Do some temps have a longer throw at cost of something?

I currently have a BD04 of which I would never write a bad review.
CLICK and scroll 1/3 down to the pictures of colors

Unfiortunaely I don’t remember which color I bought. I think 1A because it looks brightest on the pictures. (is there a way to check?)
Why do people buy the 7A with 3000K color temp? What’s the advantage.
While my BD generally works great on high I almost always have to set it to low when reading. It reflects so much it’s hard to read the text. I’m wondering 3000K suffers less from that problem.

To summarize: What are the (dis)advantages of each temp?

The short answer. Cooler temps like 6500K put out more lumens than others but can have too much of a blue tint. Warmer tints such as 3000K can have a very orange/ yellow tint, less lumens than others. Neutral temps are in the middle, most people think they shown colors more naturally. Most of the people on this forum prefer neutral. Most of my personal lights are either neutral or cool, no temp is a deal breaker for me.

I have a question right before I go to bed...

6500K is cooler.

3000K is warmer.

But 6500K is 3500 degrees HOTTER than 3000K.

Why is that?

@raccoon city, don’t go to bed yet. You are still bright this late. Would say at least 5500K :slight_smile:

Thanks for your reply. Practical question. In your personal experience, say you have to read some text in the dark. Stuff like the text on a can of Pepsi, or the chassis number of a car, a book. Just practical things.
I’m just wondering some colors are better for that when comparing at equal lumen.
For me long throw isn’t that important. 5 inches to 10 yards is what I use my flashlight for 90% of the time.

Stars man :smiley:

The hotter they are the more blue light.

Spectral Classes
Star Type - Colour - Approximate Surface Temperature

A - Blue - 7,500 - 11,000 K
F - Blue to White - 6,000 - 7,500 K
G - White to Yellow - 5,000 - 6,000 K
K - Orange to Red - 3,500 - 5,000 K

Raccoon, I don’t know, can someone help me?

ZoomieFan, neutral is probably best for that.

Although there are those far more qualified to explain, yes, the light produced by a hotter body will emit more blue light, however, I believe that the naming of 3000K light as “warm” simply relates to the orangy colour we perceive, which I agree, on a technical level, causes confusion.

The hotter an object is the more blue light is emitted by it.
Just think about red and white glowing steel. Which is hotter?

The Wikipedia explains it very well.

Red to yellow colors look like fire and the sun, so they are called ‘hot’, blue-ish colors look like water and ice so they are called ‘cool’. That convention probably comes from long before astronomy became popular and certainly came from artists, not from metalworkers or anyone that had access to high temperatures. Actually reaching 6500K (6200ºC!!!) in a controlled setting is very hard and would destroy any container so deriving the color of 6500K wasn’t possible until physics theories were developed from year 1858 to 1900.

Lookit your hot/cold knobs on your sink (if they have red/blue dots or something).

Ice/cold = blue, fire/hot = red.

So bluer light = “cool”, redder light = “warm”.

The End.





So warm / hot is red.
But you have no red when you have a low CRI LED.
This is why high CRI and especially high R9 values are important, especially for warm white LEDs.
With a low CRI warm white Cree LED skin tones still look greenish, whereas with incandescent light (tungsten) you have red in copious amounts, which looks nice and cozy.

The color of a flashlight can be matched to the color of the environment.

Lets start with two flashlights, one is 3000k, the other is 6000k.

Now lets use them in two different ambient light scenarios, outdoors in sunlight, and indoors under incandescent light.

Lets mix it up and see what happens

Sunlight, working on a car, using a flashlight to illuminate dark, shaded areas around the motor.

1. The 6000k light will look less different than the ambient sunlight that our brain is adapted to at the time.

2. The 3000k light will look much more orange than the ambient sunlight that our brain is adapted to at the time.

Conclusion, the best choice for working on a car during the day is the 6000k light.

Indoors under 3000k incandescent house light, using a flashlight to illuminate a dark closet.

1. The 6000k light will look much more Blue and glaring, than the ambient incandescent light that our brain is adapted to at the time.

2. The 3000k light will look very similar in color to the ambient incandescent light that our brain is adapted to at the time.

Conclusion, the best choice for looking in a dark closet, after the brain is adapted to 3000k light, is the 3000k light. Otoh, if I have been outside in the sun, and I come inside to illuminate a dark closet, the 6000k light will seem more natural, and the 3000k will look ridiculously too orange.


  1. During the day, shine each light on the ceiling of your kitchen, no electric lights on. Notice the 6000k looks not very blue, but the 3000k looks very orange.

2. At night, shine each light on the ceiling of your kitchen, this time with electric incandescent lights on. Notice the 6000k now looks very blue, while the 3000k no longer seems very orange.

Iow, our brain sets its white balance to the environment (this adaptation takes 30 minutes). A flashlight that matches the white balance of the environment will look most similar to what the brain is white balanced to at the time.

So, 6000k is best when the brain is adapted to 6000k, and 3000k is best when the brain is adapted to 3000k.

Additional observations I have made. A flashlight will seem “brighter”, if it is a higher color temperature than the brain is white balanced to at the time. And, a flashlight will seem “dimmer” if it is a lower color temperature than the environment the brain is white balance adapted to, at the time.

Another example
Wake up in the middle of the night in full dark. Use a 3000k light to avoid obstacles on the floor. This temperature will be relaxing, and it will be easier to go back to sleep.

Now try a 6000k light, notice it seems very blue, glaring, and makes it harder to get back to sleep.

Now reading a book in full darkness, the 3000k will be more pleasant, the 6000k will be more glaring.

Then reading a label on a soup can in a supermarket, the 3000k will suck, and the 6000k will work better :slight_smile:

Bottom line is our brain changes its white balance in response to the ambient light. Our flashlights will differ or match our brain adaptation to cool or warm light. A flashlight that approximates the white balance of the brain at the time, will look closest to what the brain is adapted to at the time

during the day, I prefer a cooler light. At night, I prefer a warmer light.

IF I had to only choose one light, I would choose 4500k… it will be more orange than sunlight, but not as bad as 3000k. And the 4500k light will be more blue than incandescent, but not as bad as 6000k. Therefore, the 4500k is sort of a least bad of both worlds :-), its an average…

I have a 3000k light on my nightstand, a 6000k light in my car, and a 4500k light in my pocket :slight_smile:



That’s a great explanation jon_slider!

So I need a flashlight with color settings :slight_smile:

Yes, choices are good

As a general rule of thumb, the more Ks you have the cooler it is. 8^)

Example : All of ma friends says 4K TVs are cooler than 2K TVs :wink:

If you have the same LED. Say example, Cree XP-L2. It will be able to produce more lumens at 6500k than the same LED at 3000k. Tint preference does not depict color actualization. That is determined by CRI. It’s just some people like Coke and some like Pepsi. Except Coke doesn’t fill their cans as full.