Hicks' Blue is one of those colours that punishes timidity. It's a deep, almost inky blue-green with real oceanic depth, and the way to do it justice is to drench the room — walls, woodwork, ceiling, the lot, all in the same colour across different finishes. That's where it goes from "nice blue" to genuinely atmospheric.
The single most important rule: don't cut it with bright white. A crisp brilliant white skirting against Hicks' Blue looks like an unfinished job and kills all the warmth. If you need a softer ceiling, reach for a deep, warm off-white like Farrow & Ball's All White (LRV 92) — it sits down quietly rather than fighting the blue.
For a proper contrast that brings out the green undertone, go warm and earthy. Dulux Copper Glow (LRV 30.1) is cracking here — that burnt-terracotta warmth plays beautifully against the cool depth, brilliant on a feature wall in an adjoining space or picked up in soft furnishings. Push it further into drama with Mylands Cigar BH.20 (LRV 11.8), a deep tobacco brown that pairs with Hicks' Blue like a good leather chair in a panelled study.
Where you genuinely want a lighter accent — trim in a hallway, say — Paint & Paper Library's Sand I (LRV 95.4) gives you a warm, creamy near-white that flatters rather than fights.
Beyond paint, this is where materials do the heavy lifting. Aged brass taps and handles, walnut or smoked oak joinery, unlacquered metals — all of these draw the green out of the blue and stop it reading flat or cold.
My advice: commit. Hicks' Blue is wasted on a single accent wall with white everywhere else. Drench it, keep your whites warm, layer in brass and timber, and you'll have a room with real depth. Always test a big sample board in both daylight and lamplight first — it shifts noticeably under warm artificial light.