How does the colour develop, and why does it get darker after I remove the paste?

The colouring effect comes from lawsone, a natural pigment found in the henna plant (Lawsonia inermis). When you apply the paste, the lawsone binds to the proteins in the outer layer of your skin. However, the initial colour you see immediately after removing the dried paste is often lighter than the final result. Over the next 24 to 48 hours, the stain oxidizes and deepens to its final rich shade. This is a normal part of the process and indicates that the pigment has successfully bonded with your skin. Because this is a surface stain and not a permanent tattoo, it will gradually fade as your skin naturally renews itself. The longevity of the design varies from person to person and depends on factors such as your skin type, the placement of the design, and how much the area is exposed to friction from clothing or water. To help maintain the colour for as long as possible, try to minimize excessive rubbing or prolonged soaking of the area during the first few days.