Dull fences are definitely out.
You either paint close-boarded wood in lush, vibrant colours or you cover it up completely. Choose two contrasting colours and create a bar-code effect. Alternatively, you could use one colour for the fence itself and a slightly lighter or darker shade of the same colour for the wooden trellis you superimpose later. Then, even if your climbing plants take forever to reach the top, you'll have a pleasant sight to look at. Use your artistic skills to paint a landscape on your fence in trompe l'oeil fashion.