The infamous Marilyn Monroe believed they do; hence her evolution from Norma Jean to Marilyn.
(Isn't she beautiful?!?)
I have no clue and I have been blonde for 10 weeks. I have not noticed a difference. What I have noticed is that I still blink when I catch a glimpse of myself in the mirror. My hair has been many different colors over the years but this is the first time it has ever been truly blonde since I was 12 years old. While I like it I am not sure that it is my favorite look. Recently my 3 year old daughter asked me why I had black underneath my blonde hair...lol... So now I am at the fork in the road. Do I stay blonde, go back to brunette or go DARK, as in black (which I have done before and is very striking)?????