Explain the concept of vat dyes and their applications in dyeing cellulose fibers, such as cotton and linen.

Vat dyes are a class of synthetic dyes that are insoluble in water but can be converted into a soluble form, called a leuco compound, through reduction reactions. Once in the leuco form, vat dyes can penetrate cellulose fibers and form insoluble pigment particles within the fiber structure upon oxidation. This process results in deep, fast colors with excellent wash-fastness and light-fastness properties, making vat dyes ideal for dyeing cellulose fibers in applications such as denim, workwear, and home textiles.