During pregnancy, it is recommended to avoid using chemical-based hair dyes due to potential risks. Mehendi (also known as henna) can be a safer alternative for coloring your grey hair. It is a natural plant-based dye that has been used for centuries. However, it's important to note that the effectiveness of mehendi in covering grey hair may vary from person to person. To enhance the color and longevity of the mehendi, you can mix it with tea water and egg before applying it to your hair. The tannins in tea help darken the color, while the protein in eggs adds shine and nourishment. Before using any new product during pregnancy, it's always best to consult with your healthcare provider for personalized advice based on your specific situation.