Ogden Nicholas Rood (1831–1902) was an American physicist best known for his work in color theory. He studied in Berlin and Munich before his appointment as Chair of Physics at Columbia University, a position he held from 1863 until his death. His book on color theory, Modern Chromatics, with Applications to Art and Industry, was published in 1879, with German and French translations appearing in 1880 and 1881, respectively. Rood divided color into three constants: purity, luminosity, and hue—equivalent to James Clerk Maxwell's tint, shade, and hue.

Rood was an amateur artist, a member of the American Watercolor Society. In 1874 he gave two lectures to the National Academy of Design in New York on "Modern Optics in Painting". Along with Maxwell and Michel Eugène Chevreul, Rood's work was an influence on the Impressionist artists and their successors. The painter Camille Pissarro defined the aim of the Neo-Impressionists in a letter: "To seek a modern synthesis of methods based on science, that is, based on M. Chevreul's theory of colour and on the experiments of Maxwell and the measurements of N.O. Rood."

Xavier Rudd is an Australian singer, songwriter and multi-instrumentalist. He was born in 1978 and grew up in Torquay, Victoria. He attended St. Joseph's College, Geelong.

He has developed a strong reputation for playing live performances at musical festivals and concerts in Australia North America and throughout Europe. His following is particularly strong in Australia and in Canada, where he has recorded several albums.

Many of Rudd's songs incorporate socially conscious themes, such as environmentalism and the rights of Aboriginal peoples. In addition to playing the yidaki in many of his songs, he has also included both Australian and Canadian Aboriginal vocals in some of his songs.

Rudd has become a fixture at music festivals worldwide including the Bonnaroo Music Festival, the High Sierra (2004 & 2007) and the Wakarusa (2005), moe.down (2003), Summer Sonic, Lowlands, Rock Werchter among others. He has performed on tour with Jack Johnson, Dave Matthews, Ben Harper, Good Old War, G. Love & Special Sauce, and Rodrigo y Gabriela.^{[citation needed]}