Debbie, I have another idea about hiding the pipes under your wall-hung bathroom sink. You could buy a nice wicker or wire basket or ceramic vase/pot to go under the sink (almost the height of the bottom of the pipes). Fill the top of the basket with silk greenery such as ferns and ivy. The green foliage will hide the pipes under your sink. You could also put scented pinecones, etc. inside the pot.

If you do not particularly like silk greenery, you could roll bathroom towels and put them (standing up) in the pot, again camouflaging the pipes. Rolled bathroom towels can look very elegant. You could even tie the rolled towels with nice lengths of lace.