Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)

Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)

Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)

Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)

Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)

Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)

Workers repaint the Potala Palace during an annual renovation of the magnificent ancient architectural complex in Lhasa, capital of southwest China's Tibet Autonomous Region, Oct. 21, 2015. (Xinhua/Purbu Zhaxi)