There are some heuchera out now that have a silverish leaf. I love the colorful leaves of the heuchera! I also have had very good luck with pulmonaria. Ghost fern has a slight silver to it, and it has done really well in my gardens. I have sprinklers set up throughout my shade gardens, that get used regularly all season long, so I don't think lack of moisture was the problem here. But,I already have several potted up so I'll try it again and see if I have better luck this time!
Rose