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
Orange (colour) signal fire, historically used at night while smoke was used during the day, to communicate with distant army units. In the Indonesian Air Force, the Air force infantry and special forces corps known as Paskhas uses Orange as their beret colour. Several corporate brands use orange, such as Blogger, Fanta, FedEx, GlaxoSmithKline, Gulf, Hankook, Harley-Davidson, ING, Jägermeister, Nickelodeon, Orange, the Women's National Basketball Association, The Home Depot and TNT. Orange, because of its common association with activity and visibility, is a popular colour for sports teams. Orange (colour) Orange is the colour between yellow and red on the spectrum of