I believe a light grey would look nice behind the blue in the map - it needs to be a perfect shade of grey as grey is hard to achieve. Possibly experiment with various colours - I usually paint on board using sample pots first then hold them up in large sheets to see what suits the area... This gives you an indication of where throws of light will capture the actual colour and which shades suite the room without having to paint on the walls. The board base colour generally needs to be as close to your existing wall colour to achieve the closest match.

Your walls could be alost any color as for the furniture I would look into the tapestry and when that is decided choose a color from it for the walls

You could do a warm or cool gray, navy blue, soft pale white, the same green. Really up to you.

Hi Idsshyam, For beige walls, white tiles/marble are a classic pair. This gives you a blank canvas to work. You can also go for darker wood tones such as mahogany or ebony flooring to contrast the lighter wall colour. A cool-tones beige would also complement maple, birch or walnut wooden floors. These can easily bring a contemporary look to your space. Hope this helps. Good luck with your home design.