According to China's "National Lighting Standard":
2700-4000K belongs to warm white.
4000-5700k is confession.
6000-7000k belongs to white.
8000k belongs to cold white.
The color temperature of lights in shopping malls and hotels is basically around 4000K K, 4000 is officially called cold white, and 4000-5000 (neutral white) is good for home use.
Supplement:
Color temperature is a unit of measurement, indicating the color components contained in light. Theoretically, color temperature refers to the color of an absolute blackbody heated from absolute zero (273℃). After heating, the black body gradually changes from black to red, yellow and white, and finally emits blue light. When heated to a certain temperature.
The spectral component of the light emitted by a black body is called the color temperature at this temperature, and the unit of measurement is "K" (Kelvin). If the light emitted by a light source has the same spectral component as the light emitted by a black body at a certain temperature, it is called a certain K color temperature. For example, the light emitted by a 100W bulb has the same color as the light emitted by an absolute black body at 2527K, then the color temperature of the light emitted by this bulb is
Color temperature and brightness: under the irradiation of high color temperature light source, if the brightness is not high, it will give people a cold atmosphere; Under the irradiation of low color temperature light source, too high brightness will give people a sultry feeling. Light-color contrast: When two light sources with large light-color differences are used in the same space, the contrast will have a hierarchical effect. When the contrast between light and color is large, the brightness level can be obtained at the same time.
Extended data
On the question of color temperature, you can look at Baidu Encyclopedia entry in detail, color temperature:
& lt3300K warm (red and white) and steady warm.
3000-5000K medium (white) refreshing
& gt5000K cold (blue and white) cold.
All belong to white, 2700-4000K belongs to warm white, 4000-5700k belongs to natural white, 6000-7000k belongs to positive white, and above 8000k belongs to cold white.
LED is a light emitting diode, which is a solid semiconductor device that can convert electric energy into visible light, and it can directly convert electricity into light. The heart of LED is a semiconductor chip, one end of which is attached to the bracket, one end is the negative electrode, and the other end is connected to the positive electrode of power supply, so that the whole chip is encapsulated by epoxy resin.
The semiconductor wafer consists of two parts, one is a P-type semiconductor, in which holes are dominant, and the other is an N-type semiconductor, mainly electrons. But when these two semiconductors are connected together, a pn junction is formed between them. When the current acts on the chip through the wire, the electrons will be pushed to the P region, where the electrons will recombine with holes, and then the energy will be emitted in the form of photons, which is the principle of LED light emission. The wavelength of light, that is, the color of light, is determined by the material forming the pn junction.