Open-plan spaces go wrong when people treat each function — kitchen, dining, sitting area — as a separate room and paint it accordingly. You end up with a patchwork that feels restless. The fix is to think in terms of one connected scheme built around a shared undertone.
Start with a single anchor colour that runs across the largest expanse of wall. Something forgiving like Farrow & Ball Skimming Stone or Cornforth White works because they hold their nerve in mixed lighting — and open-plan spaces nearly always have a mix of north and south light. That continuity is what makes a big space feel calm and intentional.
Then zone with tone, not contrast. Pick colours from the same family as your anchor so the eye flows rather than jumps. If your main is a soft grey-green like Little Greene French Grey, you might deepen the dining area with Treron or a richer drop into a green like Card Room Green on a single chimney breast or alcove. Same undertone, more depth — that's the move.
The "but what about making it interesting?" question: you absolutely can use a punchier colour, just deploy it deliberately. A kitchen island, a run of cabinetry, or one defined wall in something like Inchyra Blue or Hague Blue gives you a focal point without breaking the flow, provided your wall colours stay quiet around it.
Watch your ceiling. In open-plan it's a huge unbroken surface, so a brilliant white can feel stark against warm walls. Knock it back with Slipper Satin or a ceiling-friendly off-white from the same warmth as your walls.
Practical advice: sample large boards and move them between the different zones across a full day. Light changes dramatically from the kitchen window to the seating end, and a colour that sings by the patio doors can go flat and dingy in the corner. Test where it'll actually live, and commit to fewer colours than you think you need — restraint is what makes these spaces look considered.