Who We Choose To Be

What is more "us": our natural selves or the us we choose to become?
I am a red hair addict and despite the cost *sigh* I think I could easily be a redhead for the rest of my life (with a few adventures in other colors as well though!). A friend of mine says she will never color her hair though, because it's not "her." However, who is to say the color I was given at birth is "me?" I mean, isn't the way we choose to present ourselves more "us" than what birth gave us? I love red hair for the numerous heroines of this tone that I read when I was younger, the characteristics usually given to redheads, and the famous actresses, artists, writers associated with the color. Honestly the color is a better reflection of my personality which has been called simply "passionate." Am I a sandy brunette? Perhaps naturally, but how well does that "suit" me...?
Another perspective: my eye color doesn't express the inner me, but my eyeglass frames are a reflection of my taste. The shape, color are all conscious decisions, as well as the choice to wear eyeglasses over contacts (although maybe soon I shall have both...).
So, is your natural body (which lifestyle will shape anyway...) more "you" or do you think the choices you make are a greater reflection of yourself?
Outfit details: shirt- some shop in Japan, dress- H&M, shoes- Dr. Scholls, stockings- tights from Target cut