National Geographic : 1999 Jul
4 "White does not exist in nature," painter Pierre-Auguste Renoir is reported to have said. Fresh snow reflects nearly all incident light. Inwind-sculpted drifts, pockets reflect the blue sky, while ridges reflect the orange of sunset. Production of Indian yellow, an artist's pigment made inIndia from soil soaked with the urine of cows fed on mango leaves, was outlawed because the leaves made the sacred animals ill. 4 Some folks are fussy about their yolks. To satisfy German preference, egg producers feed chickens marigold petals and paprika to darken the yolks. Green eggs and ham are a different story altogether. • When chickens see blood, they peck. Red contact lenses prevent the birds from seeing that color-and thus from kill ing each other. The contacts are currently being tested on 100,000 chickens inthe U.S . 4 Inmates are reported to be calmer when held incells painted a specific shade of pink. That same pink sup presses appetite, while orange stimulates it. Yellow surround ings may improve the perfor mance of schoolchildren. We see a marsh mari gold as solid yellow. With their ultraviolet vision bees see an entirely different pattern inthe same flower. THOMASEISNER 4 Orange, the color, suffered an identity crisis, having no name inEuropean languages until orange, the fruit, arrived from Asia. "Orange" comes from the Sanskrit naranga, meaning orange tree. Candy manufacturers often use microencapsulat ed colors to avoid staining the tongue. Indeveloping countries some people prefer having a candy stained mouth; it boasts of disposable income. 4 In1857 William Perkin, a 19-year-old Englishman, be came the first person to com mercially produce an artificial dye. He had inadvertently dis covered the dye the previous year while trying to synthesize quinine from coal tar (left) as a treatment for malaria. Most animals and plants get their color from pigment. However, the blue inMorpho rhetenorbutterfly wings comes from light reflected by micro scopic texture variations on colorless wing scales.