But cosmetics, by the repeated admissions of its users, reflect either carnal or vain motives (ie., makes me feel better because others will think better of me).
Cosmetics are objects, which do not reflect a motive. The motive comes from the individual, which could be good, bad or neutral.
If the wearing of cosmetics ALWAYS has a motive of vanity, then the ownership of a gun ALWAYS has a motive of violence. Of course, this makes no sense. The true answer is that cosmetics, like fine clothing, a nice house, or a sports car, is not wrong in and of itself. Such things can be a sin for some people, who are overly attached to these luxuries, yet not a sin for others.
St Thomas More was the 2nd highest nobleman in England, lived in a mansion, and had all kinds of servants. Was this sinful? No, because it was part of state in life and he wasn't attached to riches (as he proved at the end of his life, when he lost all of his wealth after disagreeing with Henry VIII).
In the same way, for women who are looking for marriage or who are married, I think it's part of their state in life to wear make-up (to a degree) in order to be presentable in society. Secondly, make-up is a COMMON PRACTICE in our society, so that those who wear NONE would appear unusual and extreme, and Catholic morals does not demand we "take a stand" on areas where there are no intrinsic evils involved. In other words, this is a gray area which each person has to decide for themselves their level of vanity and the occasion of sin which cosmetics causes them.
As a man, I see no major "occasion to sin" from make-up. The occasion to sin is typically related to fashion, not a pretty face.
The chasm separating dignity from vanity is infinite.
One person's dignity is another person's vanity. It's all relative.