Bring in something on the wall behind the sofa with a lot of white. A large mirror framed in white, or a cluster of small mirrors, or a large piece of artwork. Change out the piece on the small table in front of the window to a glass vase in white. If there is wall space, you could do floating white shelves somewhere in the room.

Thanks again for the suggestion! Here is the finished product...I didn't add all the white flowers. Do you guys think I should add more?

I am an amateur lover of home decorating. I too have a very awkward long narrow living room that is 350cm by 620cm. Additionally it has diagonal traffic flow from the front entry to the rest of the flat. The owners have built a cabinet at one end for the TV, etc. I think I would make a cosy seating area at one end of your long living room. Place a grey or brown sofa at one end but not against the wall. I like the idea of a narrow console table behind the sofa with a table lamp, a plant or a large statue. This brings the end wall closer in. A peachy or raspberry carpet in front of the sofa will pick up the wall colour and anchor this seating area. (grey and some browns also coordinate with raspberry/peach). A couple of raspberry sofa cushions can help include the wall colour into your overall scheme. Single chairs opposite the sofa allows visual and actual flow down the narrow room and completes this seating area. At the other end of the long narrow living room I would place a reading chair, a floor lamp and a small round coffee table. If there is room you could have a tall bookshelf with you favourite books. What do you have on the long side walls? I have windows and doorways on both long sides. I decided to use pull up shades on the windows instead of curtains which I thought would make my narrow living room look more narrow. The wall colour is white but I think I will tone it down to a soft grey. I plan to paint the end walls a darker grey.

You've to consider some points before designing you celebration hall. 1) It should have proper sound proofing if there is too much of noise. 2) There should be more of decorative lights to give proper effect. 3)In this hall, there should be corner sitting or grid sitting, the center space or the pathway should be defined for the movement. 4) The cooling system whether its air cooling or air conditioning, it Should be effective, so must consult a professional for that. For any other help, you're most welcome