How to Make Vegetable Hair Dye. Using vegetable hair dye is a safe, non-toxic way to play with your hair color. It's especially suited to pregnant women, those with compromised immune systems, and anyone who is concerned with avoiding toxins whenever possible. All you have to do is color, let the hair dry and wash and rinse as usual.
Decide what color you'd like your hair to be. Vegetable and herb hair coloring can only produce a natural range of hair shades.
Cover grey hairs with rosemary and sage. Simmer the herbs in water for an hour and steep them for a few hours. Cool and strain the herbs before applying. Let dry completely, then wash and rinse your hair as usual. Walnut husks are another option for covering grey and work especially well for brown hair.
Try a mixture of three parts strained and cooled chamomile tea to one part lemon juice to lighten your hair toward a blonde color. You may need either to reapply this frequently or leave it in for a long time before you see results.
Use henna to add a reddish tint to your coloring. You can combine other herbs with henna to produce a variety of shades, but the red will always show through. You can also purchase darker henna that is brown-red or almost black-red, but the only way to be sure which color it will come out is to try it.
If you want the color to be more intense, leave the product in longer and repeat applications if necessary. Most homemade vegetable or herb hair dye will be semi-permanent and wash out within eight to ten washes. Never store homemade hair dye in the refrigerator for more than a day or two if wet. You can store dry ingredients or mixes in a cool, dry place until they are ready to use.