Change Gray Hair to Black Using Coffee and Indigo Powder Naturally.

Repeat an action until you get the desired result.
You may need to use this product more than once to achieve a darker shade and hide more gray hair. The more you use it, the stronger and longer the color will stay.
Added Tips:

Do a small skin test first, especially if your skin is very delicate, before applying the mixture all over your hair. Since
indigo can leave marks on fabric, it is recommended to wear old clothes when using the dye.
In conclusion, an effective and eco-friendly method to naturally color your hair is to use instant coffee and indigo powder. Apart from making your hair healthier and shinier, it also helps you achieve darker hair without using harsh chemicals. If you are looking for an at-home way to dye your white hair a stunning black, give this natural hair dye a try!