Diatomaceous earth has been reported to recolor hair. I mix it in water with blackstrap molasses and apple cider vinegar, which also have hair recoloring properties. I also do the headstand and have for decades. Headstand brings blood and nutrients to the scalp. My hair is still mostly brown, I color it on occasion, but can go for months in-between . However, I noted in the past when I was eating processed foods, sugar, drinking coffee etc., I had more gray.