What creates the impact here? The dramatic swath of blue-green curtain is the backdrop that lets the furniture and lamp shine. Far from being a traditional choice, window treatments -- whether curtains, blinds, shades or shutters -- can be modern. If you don't have the services of an upholsterer available to you and are bored of what's available ready-made, Smith+Noble is a good resource for custom windowware.
While they are not inexpensive, they are competitively priced with many ready-to-hang options, and you get the added benefit of being able to design your own look. Fancy a valance? They'll do it. Matching lampshades? Totally feasible. How about a pillow which picks up the same tones? They can help you out. We're a big fan of their woven shades; we love the top down option (see the picture above), especially in an urban apartment where privacy is key and light is necessary.