青,作为颜色,是古人认为的五正色“青、赤、黄、白、黑”中列为首位的颜色。《说文解字》分析“青”字,从生从丹,推测是一种深绿色的矿石,又加上古代“五行”之说盛行,认为世界是由“木、火、土、金、水”构成的,“五色”与“五行”相对,“青”与“木”相对应,因此古人认为草木的颜色为青色。汉语中常以“青”色形容草 Green, as a color, is the color of the five positive colors “blue, red, yellow, white, and black” considered by the ancients. “Shuo Wen Jie Zi” analyzes the word “Qing”, and from Health and Cong Dan, it is presumed to be a kind of dark green ore, coupled with the prevalence of the ancient “Five Elements” theory. It is believed that the world is made of “wood, fire, earth, gold, ”Water“ constitutes, ”Five colors“ and ”Five Elements“ are opposite, ”Green“ corresponds to ”Wood“, so the ancients thought that the color of vegetation was blue. Chinese often describe grass as ”blue"