Bone China Blue is one of Little Greene's quietest, most flattering blue-greys — soft, slightly powdery, and far easier to live with than a punchier blue. The trick with a muted colour like this is to keep its companions equally restrained, then introduce one deeper note for tension.
Start with the whites. A clean, cool off-white on ceilings and trim lets the blue read as blue rather than greying out. Farrow & Ball All White (LRV 92) is the obvious choice — properly neutral, no yellow, so it keeps everything crisp. If you want a touch more softness underfoot or on adjacent walls, Paint & Paper Library Sand I (LRV 95.4) is a barely-there warm off-white that stops the scheme tipping cold.
For warmth and contrast, bring in metals and timber. Limed or pale oak flooring is ideal, and polished nickel rather than brass keeps the cool register intact. If you'd rather have your accent in paint, Dulux Copper Glow (LRV 30.1) is a lovely muted terracotta that does the same job as a copper fitting — that warm-against-cool pairing always sings, and it stops a blue-grey room feeling chilly.
Then give it depth. A muted blue needs something to push against or it floats. Mylands Cigar BH.20 (LRV 11.8) is a deep, inky brown-black that's perfect for a feature piece, a bookcase, or interior joinery — it anchors the whole scheme without going full slate. If you'd rather stay in the blue family, an inky blue on a door or panelled wall does the same.
Practical advice: Bone China Blue shifts noticeably with light. In a north-facing room it goes greyer and cooler, so lean on the warmer Copper Glow accent and keep your white warm. In a bright south-facing room the blue comes forward and you can afford the cleaner All White. Always sample both whites side by side — that decision makes or breaks the scheme.