<P> Historically , balls were either black or white in colour , depending on the background colour of the courts . In 1972 the ITF introduced yellow tennis balls into the rules of tennis , as research had shown these balls to be more visible to television viewers . Meanwhile Wimbledon continued to use the traditional white ball , but eventually adopted yellow balls in 1986 . ref = http://www.itftennis.com/technical/equipment/balls/history.asp HUH HI hi HI hi HI hi HI hi </P>
<P> Historically , balls were either black or white in colour , depending on the background colour of the courts . In 1972 the ITF introduced yellow tennis balls into the rules of tennis , as research had shown these balls to be more visible to television viewers . Meanwhile Wimbledon continued to use the traditional white ball , but eventually adopted yellow balls in 1986 . ref = http://www.itftennis.com/technical/equipment/balls/history.asp HUH HI hi HI hi HI hi HI hi </P>
when were yellow tennis balls first used at wimbledon
when were yellow tennis balls first used at wimbledon
1986
1986