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
Rank in Judo first five are colored black, 6th, 7th, and 8th "dan" have alternating red and white panels (dandara), and for 9th, 10th "dan" and above, the belts are solid red. In judo's promotion system as originally finalized by Kanō around 1926 there was no maximal dan rank, and judoka holding 10th dan would normally wear a red belt, but also could wear a white belt, the same color as the lowest kyū rank. However, since the highest dan rank reached in judo for a living person or conferred posthumously remains 10th dan, any judo dan rank higher than 10th dan is