Has anyone here switched to a plant-based hair color or a PPD free herbal hair color kit for sensitive scalp?

I’ve been looking for a gentler alternative to chemical dyes because my scalp reacts easily to strong formulas (itching + dryness after coloring). I came across a few options that claim to be fully herbal, plant-based, and free from ammonia, PPD, and harsh chemicals basically designed for people with sensitive skin.

Some of them are made using ingredients like henna, indigo, amla, and other Ayurvedic herbs, and are marketed as being much safer for regular use without irritating the scalp.

I’m curious if anyone has actually used a plant based hair color or a PPD free herbal hair color kit for sensitive scalp long-term:

• Does it actually cover greys well?
• How natural does the color look in real life?
• Any scalp improvement over time or just marketing claims?

Would love honest experiences before trying anything new.