Indigo is a color that is brighter than pigment indigo but darker than screen indigo. The web color is #blueviolet. Pigment indigo: usually mixed with pigments or colored pencils. Indigo should not be considered a separate color, but rather a member of the blue or purple family.
Morphological Characteristics
The organic dye dark blue is made by fermenting indole indigo and plant leaves containing indole acid such as woad, wood indigo, and ma indica. It is also artificially synthesized (ancient books It says: All five kinds of blue can be indigo - Song Yingxing. "Tiangong Kaiwu"). Used to dye fabrics with long-lasting colors. It is commonly known as indigo, and in some areas it is called indigo.
Indigo is a vat dye with a history of more than 3,000 years. Xun Kuang's famous saying of the Warring States Period, "Blue, comes from blue and is better than blue" originated from the indigo dyeing technology at that time. "Qing" here refers to cyan, and "blue" refers to the blue grass from which indigo is made. Before the Qin and Han Dynasties, the application of indigo was quite common.