Truly not judging a book by it's cover has some wisdom to it albeit not entirely without fallacy (error).

Just because someone has a unique hairstyle, clothes and tattoos does not necessarily mean they are unique entirely.

I've noticed outwardly unique looking people who barely resemble each other physically have just about the same personality, mannerism, lingo etc.

Bland looking people or average looking people who look just about the same as everyone else can have very unique personalities once you get to talk to them.