UV protection of paintings

If you're using Artists' quality colours, it would take months of exposure to direct sunlight in order for your paintings to start to fade. 

If you want to display them in direct sun, frame them with UV protective glass if you can afford to, otherwise consider spraying them with a UV protective spray (Anna hasn't done this herself but members have reported good results). Otherwise, it's best to either display your work away from direct sunlight, or store your paintings in a folder or in a drawer.