Hi INTIKHAB ALAM,
Welcome to HCM. ,
premature greying of hair also known as canities .is a common problem but there is no proven treatment for the same . mostly it is determined by genetic constitution of individual.Dont pay much attention to it as grey hair are the sign of wisdom.
use good ammonia free dye for cover up.
you can take Biotin
, antioxidant supplementation .to prevent further greying.
‘Hope I have answered your query, I will be available to answer your follow up queries. “Wish you Good Health”