Is my hair grey or gray?

Your hair can be described as grey or gray, both spellings are correct and mean same color between black and white that appears when pigment loss occurs, choice depends on regional spelling. If you are in United States, your hair is gray, using American English spelling with a, which is standard in American dictionaries and official documents. If you are in United Kingdom, India, Australia, Canada, or other Commonwealth countries where British English is taught, your hair is grey with e, which is standard spelling taught in schools in India. Pronunciation is identical, only written form differs. For example, if you are in Dulapalli, Telangana, India, British English is taught, so grey hair would be expected spelling in school and official writing, though gray is also understood due to American media influence. Neither spelling is wrong, both refer to same silver-white hair color that comes with aging when melanocytes stop producing melanin. In medical context, grey hair is described as canities. If asking about actual color of your hair, only you can tell by looking in mirror, if you see silver-white strands mixed with original color, you have grey or gray hair. If you are 70 and have little grey, that is uncommon but possible due to genetics. So answer, your hair is grey if using British spelling, gray if using American spelling, both correct, choose based on location and audience for consistency.