Depends really how bad it is, as Rob says you can bring back some of the colour with a good clean. Above surface defects can be polished out, below surface means you need a re-spray.
Red is the hardest colour to look after, if it's not been waxed at least once a month then it will fade very easily.
Clean the car and try using Clar Bar on it if the paint work feels rough under hand. Otherwise get some paint cleaner, have a go with that on a spot to see if it makes any difference. Use a really soft cloth, Microfibers are perfect.