I love your outside entertaining area. It does need a color that would complement but give the area a focal point. I like the darker red,orange colors you may find in natural. You could dress up the table with accessories and place cushions in a complimentary color on the benches. Colored potting containers would also bring it all together. I like the uplighting here in the photo you could place along the back fence to add drama. Your area reminds me of Modern mediterranean landscaping.

I was about to say grey until I read the last line. What about a light brown carpet?

Looking for a shade of white to compliment the exterior cladding on our new house - don't want a shade of white that is too bright - something that will look good with "matt charcoal"

When I first looked , I thought there were blue tones in the room , and I gave up haha . But looking again , I think the main tones are grey and charcoal ? I hope so . . . . . So paint ( or wallpaper ) that whole wall . Personally , I'd go burnt orange in a paint ( which , of course , isn't all that orange ) , or something in a bright or rich red base , if wallpapered -- imagine a rich red with thin beige and mid gold vertical lines if you want a classic look for example . Then matching modern standard lamps -- 1 each end . Wall mount the TV , or go for a bigger tele ( yes , I know , a lot of people don't want that as the feature , but it is a big wall ! ) BUT add 1 or 2 prints or paintings on that wall too -- again , my personal choice would be one bigger than your TV , with bright red base tones ( against a rich red wallpaper ) , and splashes of orange and yellow and beige and blue and -- you get the idea ! An abstract landscape or racehorse or torso or whatever floats your boat -- I don't like the swirly or straight line types of art , but obviously some people do . Still look sparse ? A large colourful glazed pot or two , with suitable indoor leafy plants/cactii/similar . A big shaggy rug in a warm red or orange or orangy red . Adds life , colour , warmth -- all around a common theme . And thats why I shuddered at the initial thought of blue -- 7 different blue tones will never look as warm , and red and orange never looks as good against a blue , so you are stuck with the colder look IMO .