Color reflected color depends upon the viewing angle. Numerous scientists have carried out research in butterfly wings and beetle shells, including Isaac Newton and Robert Hooke. Since 1942, electron micrography has been used, advancing the development of products that exploit structural color, such as "photonic" cosmetics. 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
Judo at the 2008 Summer Olympics men, 147 women and 22 places not yet allocated to a gender. An NOC may enter up to one athlete per weight category. The qualifying places will be allocated as follows: Continental qualification places will be allocated through the ranking system based on the major tournaments on the continent (continental championships, qualification tournaments). More important tournaments and tournaments closer to the Olympics will carry more points. Deadline for the unions to confirm the places was May 21, 2008. Judo at the 2008 Summer Olympics Judo competitions at the 2008 Summer Olympics in Beijing were held from August 9 to August