In beauty, as in many things in life, it's the finish that is key. Which is to say that you may be bang-on with your choice of lipstick shade, but if you go gloss when the whims of fashion or the rest of your look demand matte, your efforts will fall flat.
Conventional beauty generally requires lustre – evolutionary principles demand that things such as hair, eyes and teeth must be shiny and sparkly. Skin, however, is a trickier matter, requiring a delicate balance of textures, where shine is needed, but only in small degrees.
If your skin is of an oilier persuasion, a "dewy" look – cosmetics' holy grail in this area – is unlikely to be an option (except perhaps for a five-minute period around midday), but thankfully new mattifying formulations in foundation no longer turn your complexion to chalk. The best allow a little natural sheen to develop, giving you that idealised teenage skin that most of us never had.