Using vegetable hair dye is a safe, non-toxic way to play with your hair colour. 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 colour, let the hair dry and wash and rinse as usual.
Decide what colour you'd like your hair to be. Vegetable and herb hair colouring can only produce a natural range of hair shades, so you won't be able to go for a neon pink or electric blue hue.
Cover grey hairs with rosemary and sage. Simmer the herbs in water for an hour and brew them for a few hours. Cool and strain the herbs before applying. Let them 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 camomile tea to one part lemon juice to lighten your hair towards a blonde colour. 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 colouring. 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 colour it will come out is to try it.
If you want the colour 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.