Is Your Hair Color Working for You—or Against You?

Susan Hersh, 45: Flat, Lusterless Gray

The Challenge: When Susan stopped dyeing her hair more than 15 years ago ("I was coloring it platinum—too much upkeep"), she was surprised, not unpleasantly, to learn that she had a shock of luminous silver at the center of her hairline. She never looked back, and let that patch gradually grow into a salt-and-pepper mix. The problem is that white or silver hair that's still sprinkled with dark strands often creates a drab hybrid that can make your skin look dull.