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) paint straight from the tube. Paul Cézanne did not use orange pigment, but created his own oranges with touches of yellow, red and ochre against a blue background. Toulouse-Lautrec often used oranges in the skirts of dancers and gowns of Parisiennes in the cafes and clubs he portrayed. For him it was the colour of festivity and amusement. The post-impressionists went even further with orange. Paul Gauguin used oranges as backgrounds, for clothing and skin colour, to fill his pictures with light and exoticism. But no other painter used orange so often and dramatically as Vincent van Gogh. who had