Indigotin is a blueish-purple dye that is used to produce coloring agents. There are various synonyms of indigotin, which include indigo blue, natural indigo, and E 132. Indigo blue is a naturally occurring version of the dye that is extracted from the indigo plant. Natural indigo, on the other hand, is a broad term that encompasses any dye sourced from plants. E 132 is a food additive that is used to give color to pharmaceuticals, cosmetics, and foods. In conclusion, indigotin and its synonyms are important substances with significant usage across a wide range of industries.