Larger Spare Bedroom

The larger spare bedroom will be light teal blues, white and possibly othere colors. I'm drawn to dark brown wood so it's likely I will use a dark brown platform bed, and other dark brown furniture. I'm most challenged by this room. We have a nice duvet that looks similar to the photo to the right (however the leaves are more leafy and less bulbous) that we hope to use here. This room is a challenge because I believe monochromatic is the only way to go. I'm cautious about mixing paterns or other colors.

Any suggestions?