Hi miyajima 2018 - You are very welcome! What color to paint your walls will depend on what accent colors you choose. I do think that painting the walls an obvious grey would be too much grey. (Especially since it does rain a lot in London!) What are the paint manufacturers that you have access to in the U.K. so we can tell you specific paint colors once you tell us the colors with which you would like to decorate your lovely new home? As for your other colors, so there is no misunderstanding, maybe you can upload some photos of objects in the colors that you like. They don't need to be furniture, they can be anything, a something from nature, or a room that is not your style, a piece of fabric, anything at all, just tell us what it is you like. For example, I recommended a paint color to a fellow Houzzer as looking like a pomegranate and put up a photo and another clever Houzzer found just the perfect color to match! If you have no idea where to start with your color choices, you can go to an art store and buy a color wheel for a few pounds and play with it, or you can look on line for one. If you only want blue, then you could have a monochromatic scheme, plus the dark grey calmed by the soothing, earthy neutral of your wood media unit and a wood or wood top dining table. You could have a white sofa with throw pillows in shades of blue in textural fabric such as velvet or suede. If not a white sofa, you could get a very light grey sofa, too. Do you know which blue you want? The rich blue of a Sri Lankan sapphire is marvelous- in the color thesaurus, http://mentalfloss.com/article/75713/name-every-shade-rainbow-color-thesaurus it would be either cobalt, lapis, or azure. Look how that blue goes with turquoise and greens , if you want to go into additional color. Doesn't the above remind you of a peacock feather? I just love those! We have only to look to nature for marvelous color combinations! I don't know how much mid century modern you want to go, but you could get a dining set that has the clean lines of the Scandinavian designs and mid century modern look, such as the set in the photo I posted above. You could also get a side chair reminiscent of one of the mid century modern icons such as these, or others. And brighten the space with other mid century features such as a starburst mirror of which there are many types. And for a fun pop of color, there is this Eames wall- mounted coat rack which also comes in wood if you want a more serious palette

Agree with lynartist get someone knowledgeable in to look at the walls. Shifting the color used makes a huge difference. I would not have the walls smoothed or made shiny. But there are all sorts of ways to approach this and end up with a great looking home. Consider moving the functions of the two spaces. A modern dining area with a fireplace, even such an ornate one, could be spectacular and marry well with a more intimate USED space for conversations, drinks, and even just solo book readin'! Making the switch would also de-emphasize the fireplace and allow it to look its very best. A bit of a paradox but look at many old European houses and you'll see it again and again. My other preference would be to have a wood refinisher take down the shine on the floor. Congratulations and I hope you let us know how this progresses.

I think continuing with the gallery wall would be fantastic, but the pieces look a little wobbly at the moment. I think the problem might be that they are not straight. It might also be that you are trying to put vertical and horizontal pieces together in the same size frame as the horizontal pieces. I think you need some larger pieces in the mix. I use glue dots on the corners to keep the frames straight. The smaller the frame, the more noticeable it will be if they are not straight. If you keep what you currently have, I would rearrange so that the vertical pieces are not all in the same row. @idaclaire has a fabulous gallery wall in her bathroom!

I am assuming your podcast will be video'd, so people will see your studio. The first thing I would do is get rid of the coffee table, it is totally lacking in style. I am not sure about the ottoman either. While it is nice, it is for a residential space, and in addition, the color doesn't relate to chairs, and as this is not a home, you don't have the opportunity to bring in other things to allow the blue to connect with the yellow. Under the window get a glass console table, perhaps with a shelf on which to place the products that you will discuss during your podcast. In addition, get a coffee table, perhaps a round one, on which you and your guest can place a cup and the products you are discussing. I am not thrilled with that metal window covering. Perhaps you can cover it with something? On the walls you could project photos of people carrying the products you are discussing. Or something similar. And take the photos yourself, or find classic photos.