Blue Naming of Chinese Style

Indigo is indigo. Liquid made by soaking blue grass, also known as deep blue. Indigo, an organic dye dark blue, is fermented from leaves of plants containing indole acid, such as Polygonum cuspidatum, Isatis indigotica, Indigo edulis, Malaya and so on. Blue: China traditional color terms, deep blue and cyan. Source: Ye Shengtao's "Tour Three Lakes", there are several thin clouds floating in the blue sky. Blue: a kind of blue, used to describe the color similar to a clear sky. Tang Du Fu's poem "Going to Jin Huashan in Winter" has related records.