Give it some time for the color to develop fully. Henna oxidizes over 2-7 days, getting darker and richer. Indigo dye begins as green or blue-green and transforms into a deep blue gradually. It takes about 48 to 72 hours for indigo blue to fully develop. If your hair appears yellow right after dyeing, just be patient.

To ensure that indigo develops its color properly, avoid using a hair dryer immediately after washing it off. The natural pigment needs time to develop, and drying it too quickly can hinder the indigo color development. It's crucial to keep your hair damp and exposed to the air. If you experience slow color development, consider wrapping your damp hair in a towel to enhance the process.

If you have high-porosity hair, using a strong shampoo right after dyeing with natural dyes can strip away the penetrated natural pigments more easily. Daily shampooing can lead to the continuous removal of pigments like henna and indigo, causing the remaining pigments to become faint. As mentioned earlier, dyeing with a light pigment may result in a yellowish appearance. To prevent this, it's advisable to either rinse your hair with just hot water or use a specialized shampoo immediately after dyeing it again.

For individuals with high-porosity hair, the continuous loss of natural pigments during regular washing can impact hair quality. To address this, a shift from using strong shampoos to washing with natural herbs, such as Reetha Fruit—an Ayurvedic herbal shampoo with a historical usage—can be beneficial. This transition is considered an effective method to enhance hair quality until improvements are observed.