<P> Equipment required in softball includes a ball, a bat (composite, metal or wooden), gloves, uniforms and protective gear: for example, helmets for the offensive team and a helmet, shin guards and chest protector for the defensive catcher . Also cleats, sliding shorts, face masks and knee sliders may be worn for softball . </P> <P> Despite the sport's name, softballs are not especially soft . The size of the ball varies according to the classification of play; the permitted circumferences in international play are 12 ± 0.125 in (30.5 ± 0.3 cm), in mass between 6.25 oz (178 g) and 7.0 oz (198.4 g) in fastpitch; 11 ± 0.125 in (29.7 ± 0.3 cm), mass between 5.875 oz (166.5 g) and 6.125 oz (173.6 g) in slow pitch . For comparison, under the current rules of Major League Baseball, a baseball has a mass between 5 and 5 ⁄ ounces (142 and 149 g), and is 9 to 9 ⁄ inches (229--235 mm) in circumference (2 ⁄--3 in or 73--76 mm in diameter). A 12 - inch circumference ball is generally used in slow pitch, although in rare cases some leagues (especially recreational leagues) do use a 14 - inch circumference ball . Some balls have a raised seam, and others do not . The ball is most often covered in white or yellow leather in two pieces roughly the shape of a figure - 8 and sewn together with red thread, although other coverings are permitted . The core of the ball may be made of long fiber kapok, or a mixture of cork and rubber, or a polyurethane mixture, or another approved material . </P> <P> In 2004, high - visibility yellow "optic" covering, long - used for restricted flight balls in co-ed recreational leagues, became standard for competitive play . Yellow is the color of official NCAA and NAIA softballs . Yellow softballs are fast becoming the standard for all levels of play for girls' and women's play in particular . White balls are also allowed, but are very uncommon in slow pitch and fastpitch . </P> <P> In Chicago, where softball was invented, it remains traditional to play with a ball 16 inches (41 centimeters) in circumference . The fielders do not wear gloves or mitts . A 16" softball when new is rough and hard, with hand and finger injuries to fielders frequent if they do not "give" when receiving a ball, but the ball "breaks in" slightly during a game and continues to soften over time with continued play . A well - broken - in ball is called a mush ball and is favoured for informal "pick - up" games and when playing in limited space, such as a city street (because the ball does not go as far). A 16 - inch ball is also used for wheelchair softball . </P>

When did softball change from white to yellow