Today is about color.
First the meaning is here.
Color
Color (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object’s physical properties such as light absorption, emission spectra, etc.
I am interested in the explanation about color in Japanese Wikipedia, it is something like this.
“Even with the same color stimulus, the same color perception is not necessarily established, and the results are different depending on the perception of the surroundings and the state of the observer.”
And also the explanations related to the above sentenced in English Wikipedia:
Individual colors have a variety of cultural associations such as national colors (in general described in individual color articles and color symbolism). The field of color psychology attempts to identify the effects of color on human emotion and activity.