You could use a color from the background of the paper but if that seems too dark then go two shades lighter. Is that the way you are using that furniture ? If so I think it would be better painted white.

if you want the furniture to really stand out paint the walls a soft yellow

I'd consider a soft sage or mint which would harmonize and bring out the lovely shades in the various blues.

You didn't say if you wanted something bright or muted or how much of the color would be seen, but if you like brighter colors, I'd suggest a coral, poppy, or teal colors–the furniture would really stand out nicely against such happy colors. If you wanted muted colors, a nice goldenrod yellow or crisp lavender would be a nice contrast as well.

A deep red, like burgundy.

A yellow would be a nice contrast and would make the room lively, keep it warm and soft so it doesn't jar with the stain color. A gray would be beautiful, more calming.

Do you think that the damask wallpaper and the style of furniture are too contrasting? I should mention that the carpet in the bedroom is a light beige. I would like the room to have a calming feel, but also feel bright and light. My boyfriend is hesitant about painting the walls yellow. Perhaps we should not use the wallpaper and simply use a brighter colour on the back wall? Any recommendations? This is quite the design challenge!

A monochromatic scheme uses different values (tints, shades, tones) of only one color, (with the possible small addition of white or grey). Monochromatic schemes are easy to get right and can be very effective. They are calming and peaceful for a bedroom. Check out my home design blog for peaceful bedrooms, paint colors, and 67 posts with lots of ideas. http://designsenseflorida.blogspot.com/

A warm medium shade of yellow will contrast nicely with the furniture and wallpaper, and make the furniture stand out.

What I think would look great and REALLY make the blue POP is aqua. I've seen this on a couple of design blogs lately. Combining cobalt and aqua is an interesting development in terms of fresh color schemes. Hope this helps.