The Foxglove wallpaper by F. Schumacher has a neutral base and a bright and bold pattern. It's not for the fainthearted; however, it can really make an incredible impact in a room or on a single wall.
David Hick's Hexagon wallpaper in charcoal, turquoise and fawn with pops of metallic copper is one of my personal favorites. It would be a bold choice for a powder room, foyer or ceiling in a bedroom.