Final answer:
Yellow tennis balls replaced the traditional white ones at Wimbledon in 1986 for better visibility.
Step-by-step explanation:
In 1986, yellow tennis balls were introduced at Wimbledon to replace the traditional white balls, making them more visible to players, spectators, and television cameras. This change was significant in the world of tennis as Wimbledon is one of the four grand slam tournaments, and its traditions are closely watched. The choice of yellow was found to offer better visibility on the grass courts as well as on the color television broadcasts which were becoming more common.