Color is one person's feelings, it is always with the individual's subjective experience of the observer. After each person the feeling of seeing a color, others hardly know. Therefore, the color of the imagination is always full of mystery. Meanwhile, the color they make the world a colorful, visual arts, image display and transmission, textile dyeing and printing, color printing, color of can not do without. Therefore, the color of research on the color of an objective quantitative description of the object of study for many scientists.
Newton in 1664 with a prism dispersion of white sunlight into a spectrum of different colors, light colors and laid a physical basis. 1860 Maxwell with different intensity of red, yellow, green, three out of the shade with a variety of colors from white through to light, laid the foundation for three-color study. On this basis, the 1931 establishment of the International Commission on Illumination CIE colorimetry system, and continue to improve. CIE color system is now widely used to quantify the expression of the color of light.
 

Color can not do without light, only possible in the light of objects show color, and light color on people's psychological effects are very large. Tongji University, Professor Yang Gongxia monograph in his vision and visual environment of the book's fifth chapter, made a very interesting description. (1) at different light source, the same object may show different colors. Such as green leaves in the green light, there is bright green, the red light irradiation near the black. This shows that the light source on the color of the illuminated objects appear, play an important role. Light in the light object, can be fully displayed the ability to be according to the color property, known as the light source color rendering.

How to distinguish a simple LED light bulb color index, in the absence of any testing equipment, we can only rely on intuition and their own eyes.

We can point lighting, according to their own hands, the palms appeared a pale red color that the product is high, as if the palms seem hair blue, pale skin and the color index was low.

In addition, with a colored object in different lighting, the more you feel the color, then you are under the sun feel the same degree of color object to determine a lamp color index level.

Reference article:

LED lamp, the final version of the Energy Star standards - key requirements of LED light bulbs

ENERGY STAR ® Program Requirements for Integral LED Lamps

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