Heating a standard black body with full absorption and radiation capability, the color temperature are changed when the temperature gradually increases. The black body curve on the CIE color scale shows that the black body is Red – Orange red – Yellow – Yellow white – White – Blue and white process. The temperature at which the black body is warmed up to the same or close to the light source, is defined as the correlated color temperature of the light source, called the color temperature，is expressed by the absolute temperature K.
When the light source different, the light color also will be different. The three most commonly used light color are:
- Warm white : 2700-3500K
- Neutral light (or cool light) – 4000-4500K
- Day light(Or Cool light) : 6000-6500K
When color temperature is illuminated by high brightness color temperature light source, if the brightness is not high, it gives people a cold atmosphere, low color temperature light source,if the brightness is too high will gives people a stuffy feeling.
When uses two kinds of light sources with large color difference in same space, and the contrast will have a layer effect. When the light color contrast is large, the level of light color can be obtained while obtaining the brightness level.
- Irradiation with a low color temperature light source makes the red color vivid;
- Irradiation with a medium color temperature source to make the blue have a cool feeling;
- Illuminate with a high color temperature source to give the object a cold feel
Anyway, people have different understandings of light and color. Some people like warm light. Some people like white light. Using scientific methods, different environments use their corresponding light colors, which will make the environment more harmonious.