It is a gorgeous room with lovely features. I would second Minnie's colour choices, I have Farrow & Ball Pale Powder in my bedroom and it is a gorgeous colour - like an Eau de nil but changes colour throughout the day and is very soothing. I have dark wooden floors and dark brown leather sofas like you and I think I'm going with Farrow & Ball Borrowed Light when I come to decorate to give everything a lift, a pale rug is also a great idea. The cabinets you mention I would choose white to go with your existing bookcase and also to keep things light against the walls. This is currently my inspirational living room pic, the walls are borrowed light.

Adding width BEHIND THE BED - with a headboard (which doesn't have to be a "headboard"; it could be fabric, collection of mirrors, collection of pictures, a farm gate!, small chairs or stools) across the entire width. Matching bedside tables/bookcases/chests/ with LAMPS - useful storage for extra books, extra bedding, etc. CURTAINS always warm up a room. People will always feel colder away from home - provide an extra blanket or duvet to add to the bed. I notice there is no WARDROBE. Not really necessary for overnight guests (provide hooks on the back of the door) but useful for storing your out-of-season coats, etc. There is plenty of room behind the door. Buy one on eBay and paint it to suit your colour scheme.

Why not simply fill the gap. A simply straight board like the kickboard at the base or bottom point where the cabinets meet the floor can be inserted. This can even be enhanced by using a cornice type finish and if you wish add a bit of colour to complement your kitchen . You would also choose to change colour of kickboard/plinth at the floor to keep a nice overall appearance. CJL

Im hoping for some advice on paint colours for a living room/den that has high pitched ceiling. The house is a new build. Modern barn aesthetic. We are thinking about a different colour in the den to make it feel cosy as the rest of the house will be off white + oak. Are there rules of thumb I should follow? Should the walls and ceiling be painted the same or should I leave ceiling white? Are there different rules when the ceiling is high? The pic shows the dimensions of the den. Both windows go floor up to where the ceiling starts to slope up. Pitch is 45deg. We will a TV on the wall where the SS is and brown leather couch facing Thanks Marcus