If you were in an anime, you would have hair as white as snow. You are pure, ethereal, serene, and even a little magical. Others may see you as being a little strange. You are quite strong-willed, skillful, and dignified. In fiction, there's an eerie specificity to the use of white hair. White locks on a young character mark them as mystical and arcane, whether it means they are outright magical or not. The popularity of this trope probably stems from its status as a borderline-natural hair color: white hair on a young person strikes that delicate balance of being unusual but not blatantly unrealistic. The color also lends itself well towards symbolism.