Carol - Hannah loves this bouquet. It has the amnesia roses, quicksand, and I guess white or off white. Since her dress is white, I would probably go with white. But she would also love dusty miller around the perimeter if it doesn't get too wimpy.
This page has been dedicated to neutral coloured wedding flowers. Neutral wedding flowers work well during any season and most florists will be able to advise the best type of flower to match a neutral wedding colour scheme.