A soft mossy or grey green would be my first impulse but Sarah's dark blue looks good. It depends on your kitchen ware. White porcelains will pop with the blue and earthy stoneware will go more with the soft greens. I'd add a shelf to extend from the cabinet across the tile and a pot rack or hooks over the stove.

The light carpet keeps the feeling of "light, airy, open" and that is a selling feature (big selling feature). The last thing you want is to throw in "something" only to loose the selling feature. Have a look around at some flooring options, get quotes for material+install and then use that number as the "flooring allotment" that you will offer the buyer. The room looks good. Don't mess with a selling feature. It rarely pays off.

A15) @Dara Cooke: If you can't afford a quartz or granite worktop from day one then I would recommend using a laminate worktop as a temporary solution. If you don't put tiles up as a backsplash then replacing the worktops can be relatively easy in a couple of years.

I agree, blinds, they are large windows so that is a lot of material / expense if you go down the curtain route, plus curtains may block out light. We have sliding doors like yours and have chosen to keep them free of any covering, however we are not overlooked. You might also want to consider translucent / sheer roller blinds which offer moderate privacy yet still retain a degree of visibility. We have them on our front windows for privacy as we are in a single storey house / bungalow, people can't see in (during the day) but we can see out. We also have curtains with them in the sitting room as we wanted it to be more cosy / private at night. In the other rooms we have another blind that sits over the sheer blinds, but this wouldn't work for all windows.