Which is better for covering grey hair?

Rainbow Research has more buyer reports of solid grey coverage, though some say it missed roots near the scalp. Khadi markets high opacity for grey, but some buyers say it did not color at all. Rainbow is the safer bet for the money.

Is Khadi Natural worth the extra cost?

Only if vegan and COSMOS Natural certification matter to you. Rainbow does the same henna-indigo job for $6.17 versus $26.99 at Amazon as of November 7, 2026.

Khadi lists its result as permanent; Rainbow states 4-6 weeks with gradual fading. In practice both are plant dyes, and indigo black tends to soften over time in either case.

Can either one lighten my hair?

No. Rainbow states plainly that henna has no lightening action, and Khadi is a plant dye powder with indigo. Neither will lift dark hair; they only deposit color.

Will these dry out my hair?

Rainbow buyers report both shine and dryness. Khadi buyers more often report stronger, smoother hair. A deep conditioner after rinsing helps with either.

How long do the powders keep?

Rainbow lists a 6-month shelf life. Khadi does not state one, so mix only what you need and store the powder sealed and dry.

Rainbow Research Henna Hair Color, Black vs Khadi Natural Henna Indigo Hair Color

Both are two-step henna-and-indigo black dyes with no synthetic colorants, so the choice comes down to price and how much you trust the mix. Rainbow Research is the value pick at $6.17 for 113 g at Amazon as of November 7, 2026, versus $26.99 for 100 g of Khadi Natural at Amazon the same day. Buy Rainbow if you want the cheapest proven grey coverage; buy Khadi if you want a certified vegan, COSMOS Natural powder and will pay roughly four times more for it.

Today the Rainbow Research Henna Hair Color, Black costs $20.82 less at its best price.

Ask our shopping agent

It checks today's price at every store, compares the alternatives and answers in about a minute.