Beautiful space!

You have a pretty neutral palette thus far so you have a lot of options as far as rug color goes. What would really pop off the dark flooring would be something in an ivory. This will help maintain a balance of visual weight!

Here's an idea for a rug with great tone-on-tone dimension which will be a great color and compliment the style of your bed:

Happy decorating!

The beautiful silver green in the bedspread would contrast nicely with the dark floor and bed frame.

I'm sorry, but I can't quite imagine that bed in your beautiful space that seems to call for something more sleek and modern, or at least with more clean lines.