Your photographs are lovely and very high quality. I would advise you to pick one favourite image in portrait format and have it made into a wall-mural. There are several companies that will use your own image to create a bespoke wallpaper, including Photowall and wallpaperink. Whichever firm you choose can make a bespoke, image that with fit the wall perfectly.

Hello Rachel, I would leave the arch plain as is. One fantastic way of dealing with dado and picture rails and even skirting is simply to paint it! By that I mean leave the beading off altogether and paint the separations. This was common in the servants quarters where details were left to a minimum but actually I love this look !! It not only suggests a period aesthetic but has a really modern and contemporary feel. The same can be done with skirting. With the floor have a simple bead around the edge of the floor to finish. Mask the height and paint a line. Same again to picture rail height etc etc... I would add architrave to doors only and then try my suggestions. If you really want to add detail to the skirting you can decide how high, then add beading along the top and several sections (depending on height overall of room) or base only if height minimal and skirting minimal. Then paint the lot the colour of your choosing. :))

Try Charleston Grey or London Clay --- Farrow and Ball.. These two are nice colours anyways. Worth checking out and look very similar. Make sure to get tester pots, and paint large A3 sheet with two good coats and move around the room at various times of day to see how it might look. Best of luck.

Remember to look at the aspect of the room, before going for a strong teal colour. It’s extraordinary how different the colours look, depending on whether the room faces north, south, east, or west. And don’t forget nighttime with electric lighting. Also, if your sofa is a deep teal, you could choose a much paler aqua/greeny blue, for your feature walls, and the other walls maybe an even paler shade than those, if your room is light. On the other hand, if the room is a bit gloomy, you could use a contrasting and complementary colour for the feature walls, such as a deep gold, a warm peach, or apricot, or even a warm soft pink (similar, maybe, to F&B’s Setting Plaster or Pink Ground). Depends upon what colours you actually like, as you have to live with it. Teal is basically a blue green, so if not using teal and its paler tones for walls, look for colours that are warm, on the opposite side of the colour wheel.