The building contains four main rooms and 101 secondary rooms; each of the four main rooms has a distinctive color. The Red Room (''Salon Rojo'') is used for receptions held by the Salvadoran Foreign Ministry, and the ceremonial presentation of ambassadors' credentials. It has been used for ceremonial purposes since the administration of General Maximiliano Hernández Martínez. The Yellow Room (''Salon Amarillo'') is used as an office for the President of the Republic, while the Pink Room (''Salon Rosado'') housed the Supreme Court and later the Ministry of Defense. The Blue Room (''Salon Azul'') was the meeting place of the Legislature of El Salvador from 1906, and its classical architecture with Ionian, Corinthian and Roman elements is notable. The room is now called the  ''Salvadoran Parliament'' in commemoration of its former purpose, and was declared a National Historic Landmark in 1974.