The NBA's game basketballs are submitted to the officials for pre-game inspection, and are the purvey of the officials (specifically, the crew chief for that game) throughout the game. There's only one ball, so there's no monkey business with teams using their own balls every time they gain possession. NBA game balls are subject to an extensive review process before they are used in an NBA game, ensuring that each basketball adheres to league standards.
Before the late 1950s, basketballs were generally brown. Butler University’s head basketball coach, Tony Hinkle, thought this color was not only difficult for players to see, but also for the fans. He decided to create a ball that anyone near a basketball court could easily see. The color he chose? Orange. In 1957, Hinkle worked with the Spalding Company to develop a new basketball. The orange-colored ball made its debut in the 1958 NCAA Finals in Louisville, Kentucky. Impressed with the easy-to-see color, the NCAA adopted the ball and is now a standard for all basketball organizations.