Next Tuesday is the 60th anniversary of the 45rpm single. the Guardian has a good article about this - click the title for more:
The first single, ever, was a country record by Eddy Arnold called Texarkana Baby. Arnold was managed by Colonel Tom Parker, who saw another of his charges, Elvis Presley, sign to RCA Victor in 1956. Texarkana Baby was pressed on a slightly odd green vinyl; RCA figured that, in the format wars, they needed a novelty, and so they pressed country music on green vinyl, children's music on yellow, classical on red, and "race" music - rhythm and blues - on "cerise", or what looked like orange to the average Joe. Straightahead pop was released on straightahead black.