Color 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. By defining a color space, colors can be identified numerically
Judo of national judo associations. The IJF is responsible for organising international competition and hosts the World Judo Championships and is involved in running the Olympic Judo events. Judo is a hierarchical art, where seniority of judoka is designated by what is known as the - ranking system. This system was developed by Jigoro Kano and was based on the ranking system in the board game Go. Beginning students progress through kyu grades towards dan grades. A judoka's position within the kyu-dan ranking system is displayed by the color of their belt. Beginning students typically wear a white belt, progressing through