Attention

134. One can also sin against humility by the pomp and vanity of one's attire. This is what Queen Esther calls "the sign of my pride and glory," [Esther xiv, 16] and we must keep our hearts detached from such love because such attire is only right when it is suited to our state and condition, and when we wear it with the right intention: "Glory not in apparel at any time," [Ecclus. xi, 4] says the Holy Ghost.
However beautiful the apparel you wear may be, do not allow vainglory to enter your heart; and if you have to appear in public in state, guard yourself against vanity, "and be not exalted in the day of thy honour." [Ibid.]
Excess, self-complacency, the desire to please, to attract attention to oneself, to be above one's equals, or to equal one's superiors by the gorgeousness of one's attire, are things to be moderated and subdued by humility. St. Thomas gives an excellent rule for this: "Extravagance in sumptuous apparel is to be restrained by humility." [2a 2æ, qu. clxi, art.
These necessities which we deem essential for the decorum of our state must have their limits prescribed by Christian modesty and simplicity, and not by pride or the luxurious tendency of the times. And the vanity with which our grace of bearing or beauty of face inspires us must also be restrained by humility; because "favour is deceitful and beauty is vain." [Prov. xxxi, 30]