As wines age their colouring agents in the wine will start to dissipate. Not only will the colour change it will also loose its lustre and brightness. Don’t be put off by this though – the colouring agents may disappear but mature wines will have just as much, if not more, flavour than it would have had when young.
Red wines will start to go brick-red to tawny brown with age. White wines will go deep gold to light brown with age.