Your roommate doesn’t want to have pink hair so she asks you to change it. You can’t think of a colour that would make her look cute. Then you have an idea, give her all the colours of the rainbow. Immediately you say that she has rainbow coloured hair. Even though you said a colour change her hair grows as well but instead of staying pink it goes through all the colours of a rainbow. First her hair turns violet, it grows for about 10cm and changes to a purple colour. It keeps growing and changing colour, then blue, then green, then yellow, then orange, and finally red. At this point it stops growing but your roommate now has hair that touches the floor.
Your roommate looks uncomfortable with the weight of the hair. You tell her you didn’t mean to make her hair grow and she says that’s fine as she heard you say hair colour not length. You don’t know how to fix it without getting rid of the rainbow hair. You could cut it of normally.