How is this chestnut tinting shampoo different from permanent hair dye?

Permanent hair dye uses ammonia (or similar alkalizers) and peroxide to open the hair cuticle, remove natural pigment, and deposit new color deep inside the cortex — a chemical change that grows out with a visible root line. This chestnut tinting shampoo works differently: it lays pigment onto the outer cuticle layer only, like a sheer coat of color that rinses away over several washes. Because it doesn't alter the hair's internal structure, there's no regrowth line, no irreversible commitment, and no need for a separate developer or mixing bowl. You simply lather it on like shampoo, leave it for the time indicated in the leaflet, then rinse. The trade-off is that it cannot lighten hair, cover resistant gray completely, or deliver the same intensity or longevity as permanent color. It's designed for refreshing tone, blending early grays, or testing a warmer brunette direction without the maintenance cycle of permanent dye.