Purbeck Stone is one of Farrow & Ball's proper workhorse greys — warm enough to feel inviting but neutral enough to take almost any direction you throw at it. The trick is keeping that warm-grey reading honest, and the quickest way to lose it is bright white trim. Don't do it. A blast of brilliant white next to Purbeck Stone drains all the warmth out and leaves it looking flat and a bit cold.
Instead, pair it with a warmer off-white on the woodwork — something with a creamy or stony undertone rather than blue. That keeps Purbeck Stone reading as the soft, earthy grey it actually is. Then layer in natural materials: linen, undyed wool, limed oak. Those textures do half the work for you and stop the scheme feeling cold.
For a bit of life on a feature wall or in joinery, Dulux Almost Pistachio (LRV 80.3) is a lovely soft green that sits beautifully against the warm grey without competing — gentle and fresh rather than loud.
Now the bit most people miss: Purbeck Stone needs anchoring. On its own across a whole room it can drift towards bland. Bring in a deeper greige or a charcoal to give it weight. Mylands Cigar BH.20 (LRV 11.8) is a rich, smoky brown-charcoal that grounds the scheme handsomely — gorgeous on a chimney breast or internal door. If you'd rather go cool and dramatic, Paint & Paper Library Blue Blood (LRV 16.4) is a deep inky blue that makes Purbeck Stone look considered and grown-up.
Practical advice: paint a decent-sized sample patch and look at it morning and evening, because in north-facing rooms Purbeck Stone leans cooler and slightly mauve, while warm afternoon light pulls it towards a soft taupe. Get the woodwork tone right first — that single decision makes or breaks the whole scheme.