Why is tie-dyeing only blue?

Tie-dyeing is not only blue, but also blue, which is dyed with Banlangen. Tie-dyeing is more common in navy blue, but with the development of textile industry, the colors and patterns of tie-dyeing are more and more abundant. Tie-dyeing generally uses natural plant pigments, such as Radix Isatidis, Sparganum and other natural flowers and trees, especially Radix Isatidis, which is most commonly used in tie-dyeing because Radix Isatidis contains indigo solution, and indigo solution is an important component of pigment. Tie-dyeing, batik and blue calico are all traditional handicraft varieties of textile dyeing. Tie dyeing, also known as twist dyeing or twist dyeing, is to tie, tie, sew and tie the fabric with rope and thread, and then put it into Banlangen dye solution for boiling dyeing. Batik is to use the water-repellent property of wax to draw a decorative pattern on the fabric first, and then immerse it in dye solution. Blue calico, also known as grey dyeing and indigo calico, is repeatedly dipped and dyed by the process of hollowing out, carving and scratching to prevent dyeing and form the beauty of simple blue and white patterns.