Sequential Tart has a fun piece on the geometry of the manwha love triangle, in which Jen Bomford explains how you can use hair to tell the good guys from the bad guys: short and neat is a boy you can bring home to Mom, while spiky or long hair promises excitement but trouble.
Judging from 50 Rules for Teenagers, Korean schools have the same policy as my daughter’s Catholic school: “Only your God-given hair color is permitted.”