If you haven't already read Beauty: The Semantic Rules of this Blog, I recommend it now.
The business of narrative often overlooks aspects of Beauty in its properties, or doesn't give it enough attention. For example, Twilight, the books and movies, have hugely boosted the sales of pale foundations. The Hunger Games has its own Nail Polish Line, and DC has already started to roll out Wonder Woman and other Comic Book heroine inspired lines with M.A.C.
Here, fictional character Effie Trinket's personal style dictates fashion for both the fictional world of the Hunger Games and likely, the fashion of the film's fans in the real world. Wearers can mix and match from a broad color pallette according to their own style without appearing costume-y. Effie Trinket's over the top style in the Captiol of Panem is considered "Fashion" and not costume.
The commercial advice that is illustrated here is that ultimately, the aesthetic interpretations of beauty vary pretty widely in the real world. Even in distinct fashion circles the pursuits are individual at their heart, and rather than dictating a specific style the creation of compatible options are the strongest way to market beauty products within a franchise.