What??? No, don't tell me that! I've always heard as you age you should go lighter because DARK hair is aging. Consequently, I've just had my hair highlighted. I kind of like it for a change, but I certainly don't need to look any older. Also, I'm not very objective about this kind of thing, so I guess I need to ask someone, but I can't image anyone being honest with me about this.
I used to be white blonde, and now that I'm older, and it got dirty blonde, I highlight, a warm, natural-looking adult shade. I joke with my colorist to give me the color of 2 of my dd's - both white blonde. He said that only children, up to the age of 18, can wear it well, same with black hair. The older you get (and I don't know your age), the more you want your color in the middle - nothing drastic.