Avuri Neeli - From India . Does not turn blue when mixed with water. Is it good?

Hi
I read from mehandi.com that indigo/Neeli when applied on top of Mehandi turns grey hairs black. Well, say it stress or the gift of US, I am all greyed enough at 25.
Got this Avuri/Neeli powder from a renowned Herbal store in India and had it shipped here. When I put warm water & let it stay aside for sometime, it did not turn blue. It stayed green. Not sure if I can apply it or not. On the packet, it says it helps hair grow black & that it can be taken everyday internally.

Let me know if any of you have come across this /know if it is ok to have it green & still apply. I applyed to portion of my hair (from brush ) and it didnt seem to do any harm - neither did it do any good.

Also anyone knows where I can get good Neeli/Indigo poweder that will be great. Is it ok if it does not turn blue to yet apply?

Thanks