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
Shades of orange right. This shade of orange is unique to the University of Tennessee (UT), defined by the institution as Pantone 151, and is called "UT orange". It is offered for sale by The Home Depot and licensed by the university. According to the university, this shade of orange is derived from the American daisy, which grew in profusion on the oldest part of the campus, The Hill. "Spanish orange" is the color that is called "anaranjado" (the Spanish word for the colour "orange") in the "Guía de coloraciones" ("Guide to colorations") by Rosa Gallego and Juan Carlos Sanz, a color dictionary