I normally use 50/50 twilight and indigo one step process. The indigo fades so quickly on my grey roots so I did an experiment to see how my hair would look without indigo and used twilight and amla on my roots. It is way too orange so I need to go over again with henna and indigo. My question is how long should I leave it on for? I don't want to go black. I was thinking an hour? Normally I leave on for 4 hrs but that is on grey, now it's orange I'm not sure. Thank you!!