Roof of Forbidden city

The roof form of Chinese architecture is rich and colorful. In the Forbidden City building, there are more than 10 different types of roofs.
Take the three halls as an example, the roofs are different. The roof of the Forbidden City is full of glazed tiles.
The main hall is mainly yellow.
Green is used in the construction of the Emperor’s residential area.
Other blue, purple,  green and malachite green, sapphire blue and other colorful glass, used in gardens or glazed walls.
Black roof used in the library as it is indicate “water” in the five elements theory and can again fire for the preservation of library.
Hall of supreme harmony-where the emperor’s succession ceremony held (yellow roof)
Hall of literary profundity-Library (Black color roof)

Hall of Sound Growth of the Successor–The prince’s residence(Green color roof)