If you'd like people to think that you're younger than you are, consider adding contrast to your face. The contrast in color and tone between human facial features and the skin around them decreases as we age. Skin becomes less luminous, lips lose their redness, and even eyebrows become lighter. And although we aren't consciously aware of it, our brains notice the amount of contrast and use it to guess a stranger's age. In one study, participants looked at images of people, some of which had been enhanced to increase contrast, and universally guessed that the people in the enhanced images were younger than they actually were. The findings appear to validate the use of cosmetics, which are often applied to provide increased contrast.
Face the facts: