Well, there could be a fanfiction where Bella dyes her hair purple by accident. Maybe she was trying to use a natural hair treatment but something went wrong with the ingredients. Her friends are initially shocked but then they start to love her new look. This new hair color also catches the eye of a certain character who previously hadn't noticed her much, and it sets off a whole new series of events in the story.
Shikamaru might just sigh and say something like 'What a troublesome thing to do, Naruto.' But deep down, he would also be a bit curious about why Naruto decided to dye his hair red.
Maybe he just wants a new look. Naruto is always known for his wild and adventurous spirit, so dyeing his hair red could be a way to show his rebellious side or simply to stand out more.
It could be related to a specific event in the fanfic. For example, if she's going undercover for some mission, changing her hair color might be part of her disguise. Also, perhaps she's influenced by someone she admires and decides to copy their hair color.
She might choose blue. Blue is often associated with intelligence and mystery, which suits Hermione well. It would be a bold yet still somewhat sophisticated choice for her.
Maybe it's a magical protection. In the wizarding world, there could be some ancient magic associated with hair length. Long hair might act as a sort of shield or a connection to some deeper magic that Harry unknowingly benefits from.
Maybe he wants to change his look to disguise himself from his enemies. In fanfiction, there could be all sorts of threats and he might think a new hair color would help him blend in or not be recognized so easily.
Some might find it charming. For example, his friends like Ron and Hermione might see it as just another part of Harry's unique personality. It could make him seem more approachable to those who are drawn to his non - conformist ways.
He could dye it black to look more mysterious, like a dark wizard in disguise. Or perhaps he'd go for a bright red, which would make him stand out more and show his boldness. Another option could be a platinum blond, giving him a completely different look, maybe to imitate a famous wizard from history.