Judging from the present meaning, "Danqing" refers to painting, which often appears in written language. When people describe people who are good at Chinese painting, they will say that they are "good at Danqing", while painters with high attainments in Chinese painting, such as Wu Changshuo, Qi Baishi and Zhang Daqian, are often regarded as painters of Danqing, which is a kind of honorific title with admiration.
The word "Danqing" first appeared in Zhou Li Qiu Guan Zhi Jin: the precept of Danqing, a precious jade and cassiterite.
The original meaning refers to red cinnabar and blue-green pheasant, two natural mineral pigments, because when Chinese painting was first born in China, people had no concept of color and technique, but simply described what the eyes saw. After the painting, in order to increase the decorative effect, they picked common cinnabar and pheasant minerals from nature and ground them into fine powder as painting pigments. Over time, the word "Danqing" came into being.
Later, people gradually discovered many natural minerals with rich colors, and applied them to Chinese paintings after processing, gradually enriching the pigments and color composition of Chinese paintings and drawing more beautiful paintings, but invisibly increasing the labor costs of painters.
Before painting, the painter has to consider many problems, such as how to draw lines, how to make a composition, how to fill colors, how to refine the artistic conception of works, etc., which makes the painting process more complicated.
In order to draw satisfactory works, painters have to spend a lot of time thinking. Therefore, the word "Danqing" has gradually evolved from a painting pigment into a painting process, or a painter, which has similar meanings to modern "painters" and "artists". For example, Du Fu said in the poem "Dan Qing is a gift to General Cao Ba": Be loyal to your art, you don't know your age, and let fame and fortune drift by like clouds.
After the Tang and Song Dynasties, Chinese painting ushered in a period of rapid development, and various techniques became more and more perfect, and more and more people painted. The imperial court will set up some institutions, such as Hanlin Painting Academy, to support people with painting skills. These people have a full-time title, called "court painter", and no longer use "painters" to refer to their status.
It was also in the Tang and Song Dynasties that the word "Danqing" became a written language in Chinese painting and was fixed.