A vibrant exterior that competes with the barrage of media images of Times Square. Beginning in early 1998, Viracon, a glass manufacturer based in Owatonna, Minn., sent dozens of samples of glass to Arquitectonica, which selected 10 base colors: copper, gold, bronze, orange, white, silver, violet, green, blue and aqua. Viracon would ultimately produce 8,000 glass sheets in those colors, and in clear glass panels, for the 184,000-square-foot outer wall of the hotel. As in most modern construction, the outer walls bear no weight and are simply attached to the steel or reinforced concrete structure of the building. These curtain walls are there to keep the heat and air-conditioning in and the weather out. They also establish the look of the building. Because of the curves on the north and south facades and the selection of multiple colors of glass, very few of the aluminum-encased glass panels are alike, complicating both the manufacture of the facade and its installation with 1,200 to 1,300 unique panel types.