Indus Valley 100% Botanical Hair Color (Blonde)

Can I use this color Over gray hair to look like highligh over my black hair

Yo no ablo ingles,necesito saber como se prepara este tinte para aplicarlo

Has anyone had any luck with getting their hair a light blonde with this and not on any natural color other than grey?

I got light blond and mixed the powder with the gel as it was instructed applied and left it 1 hr but my gray which is 90% did not changed at all?