Grades and quality of henna powder can be determined by its colour, purity, and fineness. When you buy henna, remember that the substance marketed for hair colour is less refined and may contain ingredients. Henna or Heena for body decoration is generally more filtered and pure. The most expensive henna is finely ground (like telcum powder), with few leaf or twig fragments; it is fresh, nearly dustless, pure and soft green. It gives the brightest color.
To vary your henna hair colour, stir some of these color enhancers into the henna paste mixture:
Allspice, cinnamon, or nutmeg : if the smell of henna is not exactly to your liking, add ¼ teaspoon (about 1 g) allspice, cinnamon, or nutmeg to the paste.
Apple cider vinegar or lemon juice Add 3 tablespoons (45 ml) vinegar or fresh lemon juice for golden or copper highlights. This treatment also is beneficial for oily hair.
Egg yolk or whole egg An egg yolk or a whole egg will help condition and add shine to the hair. Use the yolk for dry hair, and the whole egg for oily hair.
Cloves deepen and enhance the color of henna. Grind ½ tablespoon (3 gm) dry whole cloves to powder and add to the henna paste.
Cognac Add 1 tablespoon (15 ml) cognac and 1 tablespoon (15 ml) olive oil to effect a redder henna colour.
Tea To set the henna color, steep a full-bodied tea for 20 to 30 minutes. Substitute the tea liquid for the required water in the paste. Black China or Ceylon tea adds golden highlights to brown hair.
Coffee To tone down the reds and deepen the browns, use brewed-not instant-coffee as substitute for the water in the paste. Brew at least 1 cup (260 ml), bring to a boil, and then let the coffee sit as long as possible (overnight is preferable) before adding to the henna mixture.
Olive Oil The addition of 2 to 4 tablespoons (30-60 ml) of olive oil conditions and moisturizes hair. This is particularly good for dry, brittle hair.