Greetings. It's unusual to have grey hair in the public area, unless you have grey hair in scalp too. This  early greying of hair is often genetically mediated. However can sometimes occur due to malnutrition and deficiencies and also hormonal/ thyroid issues. However, it's mostly of cosmetic importance only and best shaved away. See a qualified dermatologist near you. Further queries may be sent on follow up messaging. Warm regards.