Blue is one of the most forgiving walls to decorate around, because it sits opposite warm tones on the colour wheel — which is exactly why those pairings sing.
The single best move with blue is to bring in warm earthy contrast. A burnt terracotta like Dulux Copper Glow (LRV 30.1) against a deep blue is a proper showstopper — think cushions, a feature chair, or a painted alcove behind shelving. It's the complementary relationship doing the heavy lifting, and it stops a blue room feeling cold or clinical.
For trim and ceilings, go crisp. Farrow & Ball All White (LRV 92) is a clean, undertone-free white that keeps blue looking sharp rather than muddy — it won't drag any unwanted yellow or grey into the scheme. If you want something a touch softer and warmer for woodwork, Paint & Paper Library Sand I (LRV 95.4) is a barely-there warm neutral that takes the edge off without losing brightness.
For depth and grounding — skirting, a fireplace surround, or furniture — a rich brown like Mylands Cigar BH.20 (LRV 11.8) anchors the scheme beautifully. Brown and blue is a classic, slightly menswear-y combination that reads expensive every time.
The "but what about" question I always get: *will any blue take these?* Mostly yes, but match warmth to depth. A pale, dusty blue wants gentler accents — soft tans and warm whites rather than a screaming terracotta. A deep navy or inky blue can handle the full whack of copper and dark brown without blinking.
Avoid pairing blue with cool greys unless you're deliberately after a quiet, restrained scheme — it can tip the whole room flat and lifeless.
Practical advice: pick one warm accent and repeat it three times around the room. One terracotta cushion looks like an accident; three looks like a decision. Always test your white against the blue in the actual room — north light especially can make a white look grey next to a cool blue.