Jackson and Diana Ross. The 1960s-style decorations were removed in 1980. The banks of ramps resulted in the outer wall of the stadium jutting out where the banks existed. The design also allowed for Shea Stadium to be expandable to 90,000 seats, simply by completely enclosing the grandstand. It was also designed to be later enclosed by a dome if warranted. In March 1965, a plan was formally announced to add a glass dome and add 15,000 seats. The Mets strongly objected to the proposal. The idea was later dropped after engineering studies concluded that the stadium's foundation would be unable to support the weight of the dome. The distances to the right and left field foul poles were initially both . There was a horizontal orange line that determined where a batted ball was a home run or still in play. In 1978, Manager Joe Torre suggested moving in the fences to in the corners with a wall in front of the original brick wall, to decrease the number of disputed calls. Originally, all of the seats were wooden, with each level having a different color. The field boxes were yellow, the loge level seats were brown, the mezzanine seats were blue, and the upper deck seats were green. Each level above the field level was divided into box seats below the entrance/exit portals and reserved seats above the portals. The box seats were a darker shade than the reserved seats. The game ticket was the same color as the seat that it represented, and the signs in the lobby for that section were the same color as the seat and the ticket. Before the 1980 baseball season, they were replaced with red (upper deck), green (mezzanine), blue (loge), and orange (field level) plastic seats. Unlike Yankee Stadium, Shea was built on an open field, so there was no need to have it conform to the surrounding streets. Before Shea Stadium closed in 2008, it was the only stadium in the major leagues with orange foul poles. This tradition is carried on at Citi Field as the foul poles there are the same color. After the Jets left Shea, the exterior of the stadium was painted blue and white, two of the Mets' team colors. In 2003, large murals celebrating the Mets' two world championships were added, covering the two ends of the grandstand. The 1986 mural was removed