Often, in the description of the color of light emitted by the source, we see various options: warm, cold, natural, neutral, daily, etc.
When we bought an ordinary light bulb - nobody gave us such a choice. What to choose and how to choose to don't go crazy?
Well, white light for lighting purposes is divided into several areas:
Warm white light (color temp. up to 3300K) - This is the color corresponding to the light emitted by incandescent source, ie. regular or halogen bulbs, which we used to use for interior lighting. So if you are not sure about the color of the light, which should be applied, and so far you have used light bulbs - Chose a warm white color.
If you build new lighting system you should be guided by the principle that the color of warm white fits best to the classic, subdued interiors. This light is different than the light that illuminates the sky during the day, but it is the same light which we used to use for interiors. In addition, warm color of light is best, if we want to give the room a relaxing or even romantic atmosphere. In other words, if in the room you want to relax, warm light color would be good choice.
Cold white light (5300K and more), also called daylight, is the color closest to the color of sky during sunny, cloudless day. It seems to be almost blue. It is color that stimulates us, but it is also little practical in most interiors. Cold white light is often used in specialist applications., eg. in commercial surface, in industrial zone or in aquarium.
Neutral white light (3300K - 5300K), also known as "pure white" - this is the light that cause the human eye the impression of flawless, "pure" white. It is often mistakenly called a cold color. But if you compare only two colors - neutral and warm, you can afford to name a neutral light "cold". This simplification is narrowing of classification. You should be aware of this. Unfortunately, manufacturers often use this system. In that way - buying LED described as "cold white", you can never be sure whether, in fact, get the color of cold or neutral. This is notorious for low-cost, low quality "LED bulbs" with a several of diodes inside.
Let's back to the main question - when you should use a color neutral white (sometimes called cold)? This color is ideal for rooms decorated in a modern or raw style. If you love white-black contrasting colors - use neutral colors of light to accentuate effect of contrast. This color is perfectly integrated with metal, glass, black-and-white surfaces.
Neutral white color is very often used in hospitals, doctors' offices, industrial lighting, but often it is used also for lighting of commercial space. (With some exceptions, eg. Bakers - bread lose all their optical quality, if it have been lit by color other than warm.) Note that the color of neutral and cold have stimulating properties and should not be used when you want to rest. These colors perfectly suited to reading, office work and studying. This type of light "cheat" our brain and extend period of its activity, because light is "similar" to the conditions of the day.
The neutral white and cold color are also suitable to make excellent lighting of commercial exposition. If you put two identical objects next to each other, one illuminated by cold color, the other by warm - the human eye will be attracted to object illuminated by cold color. You have to be careful when lighting objects / areas in which color reproduction is important. If it is important to all colors were clearly visible – you should look at the quality of LEDs used. You must choose high quality LED, which is characterized by high color rendering index (CRI). Many Manufacturers of Low Quality LEDs overstates that parameter in the Technical Data. So let's trust the prestige of best LEDs manufacturers who claim plausible parameter values.
White NATURAL light (!?) - It's description encountered more and more often in trade nomenclature. Usually it refers to the color neutral (but we met a few different interpretations). It is unprofessional figment of people who:
- Think they know something about the lighting and, of course, they are wrong.
- Learn from those described above.
- Knows that they express bad, but they do it consciously, to create a room for maneuver if there appears some controversy about color temperature. ( Every color can be called "natural" because in the end, all derived from nature.) Any standard or professional nomenclature does introduced such a name ("natural") so far.
- They are victims of dyslexia, and they read the word "neutral" as "natural", committing mistake that shows their lack of knowledge.
- Committed mistake resulting from a combination of the above possibilities.
Somewhat more difficult is the subject of lighting of indoor work places. This is a matter governed by specific rules, which is beyond the scope of this article.