Are additives necessary for vegetable hair dyes?Updated 6 months ago

We recommend using out hairdyes with clear water only, since they're designed to be used like that and additions to your mixture might change the result drastically.

The exception are red shades that do not contain indigo (Pure Henna, Auburn Red), in which additives such as apple cider vinegar or lemon juice can intensify the red color. 

For a particularly cool blue-black (for Pure Indigo), a teaspoon of alkaline salt or baking soda can also be added.