Gettysburg College Psychology Professor Richard Russell found that the what makes us perceive a face as "feminine" or "masculine" has a lot to to with the contrast of the face. Women, it seems, have a higher contrast between our eyes, lips, and surrounding skin than men do.
For example, regardless of race, female skin is known to be lighter than male skin. However, the eyes and lips aren't lighter or darker in either gender.. therefore making the woman's lips and eyes to stand out more- having more contrast. A masculine face usually has lips and eyes that blend in more to the color of the face.
Professor Russell learned that faces can be "manipulated" to appear more female by increasing facial contrast, or more male by decreasing facial contrast.
"'Though people are not consciously aware of the sex difference in contrast, they unconsciously use contrast as a cue to tell what sex a face is,' Russell said. 'We also use the amount of contrast in a face to judge how masculine or feminine the face is, which is related to how attractive we think it is.'
Given this sex difference in contrast, Russell found a connection between the application of cosmetics and how it consistently increases facial contrast. Female faces wearing cosmetics have greater facial contrast than the same faces not wearing cosmetics. Russell noted that female facial beauty has been closely linked to sex differences, with femininity considered attractive. His results suggest that cosmetics may function in part by exaggerating a sexually dimorphic attribute to make the face appear more feminine and attractive."
In the black and white photo above, you see two faces. The one on the left appears female, and the one one the right appears male. Looking closely though, you see that every feature is identical. Same eyes, same mouth, same nose. The only difference is the contrast of the features.
Using this knowledge, you can see that there are definitely correct and incorrect ways of using makeup to your advantage, ladies. (And gents!) Pastel lips and lots of foundation all over your face might cover up some unwanted blemishes or match your outfit, but it does the opposite of what you'd want it to. Makeup at a minimum always gives the illusion of natural beauty- but use those beauty products to your advantage. Enhance what you've got, and you'll be the most attractive you possible!
Quotes excerpted from http://www.sciencedaily.com/releases/2009/10/091020153100.htm