I wouldn't worry about being too bland. So long as you have good contrast with white- it is in your wall decor and draperies, furnishings and accessories that you will keep from being bland. I think especially when your floor has a color- a nice light neutral is a good idea. Have some confidence with your decision. I also talked about the lighter trend of walls back in may of 2009 in this post.
Go check out Ancient Marble SW6162 by Sherwin Williams. It is light overall when up- but still dark enough to contrast nicely with white woodwork.... I also really like Wool Skein SW6148- it is a little more neutral- Ancient Marble has a bit of a green tint to it- both I think would be nice with your green tile.
Wool Skein is in the photo at the top- and Ancient Marble is the square above.