I'm a person who helps people create characters for books, and I've been looking and looking, but I could never find a word that had the meaning of 'something someone wants to change most about their appearance'. It is an odd request, but I have the distinct feeling that something should exist out there. For example:
- They would be willing to do almost anything to anything to change their height.
- Personally, they thought their brown hair was just so dull- to bad they couldn't afford to get actual hair dye.
- Blue eyes were plain- why not get coloured contacts instead?