Just a little ceramic information to share as a potter. Vitrified simply means the clay has become glass like by being fired to its proper maturing temperature. Usually ceramic tile means it is a lower temperature clay like earthenware or terra cotta. Porcelain is fired to the highest temperature and is more vitrified if you will. This usually means it is less porous to to absorb water and harder. Low fired ceramics with glazes much darker or lighter than the clay body will show chips easier. Rectified has to do with making the edges precise enough to fit smoothly together for less grout lines. So porcelain cost more to produce but it is more sturdy. All clay tiles should be vitrified.

Thank you for posting the pic. Is it just open space opposite the chairs and a blank wall with the entry door? Any windows on that wall? Is that a table showing on the right of this pic, or a counter between living room and kitchen? My first thoughts are that those chairs must be pulled away from the wall and angled in some way, and somehow you need to find space for more seating. Could you angle them towards each other against the room divider, or is that a cupboard you need access to? Then you could turn the table 90 degrees, and place other seating facing the chairs. I'm liking the idea of picking up on colour from the green glass on the table, but I'm not sure how yet. I have a busy day ahead but I hope to check in later.

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.

I love dark shades but from my experience oil stains on a dark shaded cabinets in kitchen specifically are more prominent.