DEAR HARRIETTE: I recently dyed my hair a fun color, and one of my girlfriends criticized me for trying to look younger than I am. I am a 50-yearold woman, and I work in the arts. She works in a corporate job, wears a conservative hairstyle and has let her hair go gray. I have the freedom to do what I want and look how I want, so I decided to have some fun with my hair. I didn’t appreciate her cri…