- Why does kaneki have black hair again?
- Why did Kanekis hair change?
- Why is Haise’s hair turning black?
When kaneki became an investigator , his rc cells were suppressed which made him more of a human(still a ghoul though) and due to that his hair started to return back to his normal colour(black) , rc cells affected his melanin levels.
kaneki had a black hair that changed white because of the stress and fear he was endouring while getting tortured 2-3times a day for 10 days.
“Blood… my skull is split and I taste honey.” (Haise, :re Chapter 53) Kanae repeatedly kicked him in the head, he cracked his skull and that’s why his hair is covered in blood now. Most Mangas have a black-and-white style, so his hair has shown to be black because of the blood.