In search of the spectrum's elusive yellow.
D003116:Color; D004739:England; D005858:Germany; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D008027:Light; D010825:Physics / Q000266:history; D013057:Spectrum Analysis; D013472:Sunlight