The colour gives the first clue to character. White wines become more rich in colour as they age, from "lemon" to "straw", particularly if they have been oaked. Red wines, conversely, turn from purple to a "brick-red" with brown hues as they age. A vibrant red hue thus suggests youth, with the exception of Pinot Noir, which is pale and a little brown even in youth. Also detectable is the clarity of the wine, the absence or otherwise of bubbles or effervescence, and the presence of sediment.