root touch ups that work

[mamaherrera]

I'm trying to find a root touch up that doesn't make your whole scalp black and does actually cover up white roots because even though I henna my roots every week, the ones at the hairline are visible before that. Wanting something, quick, safe, and effective. If anyone has any tried/true solutions, please let me know. Thanks

[Obsidian]

I don't know if there are any good veggie dyes in black but I've used adore in a shade that matched my henna. Wasn't perfect at covering grey but it helped hide them until I could do all the roots
Another option in fanci-ful. It comes out in one wash but is easy and quick. Just apply and let dry.

[lapushka]

This means you need to move back over into chemical dyes (and there's root touch ups by multiple brands in the drugstore), or either use a veggie dye like Manic Panic or La Riche Directions or some such, but I don't know how well that would cover gray hair.