TROUBLESHOOTING GRAY COVERAGE PROBLEMS
Sometimes people have trouble getting indigo dye uptake on their gray hair when using either a “hendigo” (combined henna and indigo) for brown, or a 2-step process (henna followed by indigo) for black. If you rinse out your indigo or hendigo and find your roots are orange instead of brown or black as you hoped, here are some pointers for getting your indigo to work better on those stubborn grays.
Preparing the hair:
Wash your hair without conditioner right before using the dyes. Using a strong detergent like a clarifying shampoo or even dish soap is sometimes necessary in order to strip the hair enough to make it receptive to the indigo. Your fresh new roots are not weathered as much as the rest of your hair. They're the healthiest, most intact and least porous hair on your head, and that can make it harder for the dyes to penetrate and bond with the hair. Apply indigo, or mixes containing indigo, to freshly washed (not this morning, not yesterday, right now) and damp hair.
Preparing the paste:
Indigo is best mixed with warm water and about a tsp of salt per 100 gm of powder. Simple is best with indigo. Mix it with enough water that you get a creamy, kind of fluffy paste. Now you are ready to add your indigo paste to your dye-released henna paste, if you're doing a 1-step hendigo for brown. Or apply indigo paste to freshly rinsed, just-hennaed hair (don't use conditioner after rinsing out the henna, before the indigo) if you're doing a 2-step process for black.
If you are using indigo by itself, you'll notice it tends to thicken up as you're working with it. You might need to add a little more water partway through your application; if it's too thick it will be clumpy, hard to spread on the hair, and tend to fall off in chunks. A bit more water will help if that happens, but try not to stir excessively since you don't want to incorporate a lot of extra air, either.
How long to leave the paste on:
For a 2-step process, leave your henna on long enough (2 to 4 hours) to get a good, solid base of orange color; this will help the indigo form a better bond in the hair. Using acidic liquid in the henna step is important for most permanent color; using boiling water, for example, will result in rapid fading. Leave the indigo step on for 1 hour or a little longer for a rich black.
For a 1-step “hendigo” mix for brown, you will leave it on as long as your strand testing determined. Some people like their color with a shorter application time of 1.5 to 2 hours, longer application times (perhaps 3 to 6 hours) will give you a richer color and better gray coverage.
Adding amla to the henna can help indigo work better, too:
Whether you're using a 1-step hendigo or a 2-step henna/indigo process, the use of amla in the henna portion will give maximum results from your indigo for darker, cooler shades of brown (or black, with a 2-step) with less red tones, and less fading of the indigo.
Take about ¼ amla powder and ¾ henna powder, mix together with distilled water and let the paste rest for 12 hours for dye release. No additional acidic liquid is needed since amla itself is acidic.
Alternatively, you can prepare your henna paste as usual with a mildly acidic liquid, then when you have dye release, mix amla powder with water and stir amla paste into the henna paste. If you are using a hendigo mix, you can at that point stir in the indigo paste.
You wouldn't add amla powder directly to your indigo powder or paste because the acidity would inhibit indigo dye release.
Additional tip to prevent indigo fading:
We've had feedback on the forum indicating that in a 2-step process with hendigo as the second step, applying to DRY hair helps prevent fading of the indigo.