Old Chinese buildings are beautifully decorated. Listening to the tour commentary whilst at the Summer Palace I received an explanation as to why this is so.
The buildings are made out of wood, which deteriorates in different types of weather, painting the wood helps protect it and lengthen the life of the building. At first the wood was just painted black, but then different colours and decorative styles came to be used. What's left for us to see now are some really beautiful old buildings decorated in vibrant colours.
These are some examples from the Summer Palace.
The staircase at Longevity Hill.
I'm going to assume that the brighter colours show that these decorations have been restored.The Long Walk has paler decorations, still beautiful though.
Two examples from The Temple of Heaven, another stunning monument to visit in Beijing. The artwork here was restored prior to the Beijing Olympics.
(Noticeable difference in quality of photos from The Temple of Heaven due to me now having a better camera!)