I had a similar situation in a house I moved into years ago. I did a quick fix of painting all of the walls, woodword and the cupboards the same shade of cream. Sounds a bit OTT but it really knocked back the cupboards, which in all honesty are not something you want to make a feature out of, and created a calmness to the whole space. In your case, I would go for an off white so that the gang plug wires, radiator pipes and covers hiding the wires for the extractor fan etc., are disguised as much as possible -- that will tie in with the palest of the tiles in the splash back, and then you will have a pretty basic colour scheme of a very place colour and the dark worktop, fireplace and floor, which will stand out more. I think you need more storage with doors -- that bookshelf isn't doing anything for the kitchen. If you could get something in there that could hide lots of clutter -- even if just something cheap from IKEA, that would help greatly. Or work something around the filing cabinet that you have? A huge cheap mirror over the fireplace would bounce some light around too. If you don't want to go for undercupboard lighting, and if you have enough plug points, how about some lamps on the worktop, especially at the FF end with a floor standing lamp at the end with the chair. For the table, I would go for a table cloth and reupholster the chairs if they are not to your taste. A new blind in a much fresher colour would be great. Depending on the colour of your filing cabinet (if you use it), I think a petrol blue could add a nice vintage vibe to the chimney breast, and make more of a feature of it. I would try and go down a vintage/slightly industrial route rather than country. You may have some stuff lurking around that you could use, once you have got the base colours right -- currently it just feels a little cluttered and a bit of a mish mash. Best of luck. Looking forward to seeing some after shots :)

You certainly have the height to carry such a look but I wonder whether you would lose the definition in some of that beautiful cornice? I like ceilings painted the same colour as the walls. I considered one shade lighter (ie ammonite) to have a slight contrast. You could also paint the cornice white and the ceiling cornforth but I think that is a more traditional look. On balance my favourite would be the cornice and ceiling painted one shade lighter. What have you done in the rest of the house with the ceilings?

Lovely link thank you carolins. I have spent hours looking at IKEA hacks. HI minnie and no I dont do DIY, a terrible at it sadly! The alcoves are just over a metre wide which is tricky with billy bookcases, the skirtings are fab, they are huge, around 30cm tall and moulded and there is a picture rail too. I would have the shelves up to this point. There are sockets at the back of the alcove so I need access to these so any shevles would have to be fitted above these. I did wonder about doing sth like this (using two sets of billys with a dividing upright in the middle to fill up the alcove width) but the shelves are a tad shallow and am worried it might look a bit cheap....? http://www.ikeahackers.net/2015/06/billys-alcove-alchemy.html

I think you've found a way to solve a problem many of us has. Certainly I have - a horrible gap that isn't big enough for another cupboard and is, in the meantime, a major dust-collecting spot. I think coving would make it look rather muddled; I like the sleek look you have already achieved. Filling the strange-shaped gaps will be tricky but a careful carpenter should be able to cut the plinth/cover to fit so it matches. I think it's great.