Red means the social soil. The ancient mound of the Agency, the Son of Heaven to earth colored symbolic and central square. South Sechi, a symbol of the South to red soil.
Translated by Google
Red earth
Clay. "The book Taishi on" "Burning Sunburn good people," Tang Shu Standard Interpretation: "Wen Wang Xian Losey land, red soil of the field square miles, please Zhou except Baoluozhixing." Chen Yi "from Beijing to Guangzhou," poem: "Shaoshan Chong in view scenery, Ai Ai Ching Chung embedded red soil. "