Qin Shi Huang also followed the school of the five elements, earth, wood, metal, fire and water. () Zhao Zheng's birth element is water, which is connected with the colour black. It was also believed that the royal house of the previous dynasty Zhou had ruled by the power of fire, which was the colour red. The new Qin dynasty must be ruled by the next element on the list, which is water, represented by the colour black. Black became the colour for garments, flags, pennants. Other associations include north as the cardinal direction, winter season and the number six. Tallies and official hats were long, carriages wide, one pace () was .