Empire Grey No.171 is a deep, smoky grey-green with real warmth in its undertone, so the trick is to lean into that warmth rather than fight it. Whatever you do, keep blue-whites well away — they'll make Empire Grey look cold and a bit dead. Go warm on the woodwork instead.
For trim and ceilings, Farrow & Ball All White (LRV 92) is the safe bet — it's a clean, soft white without a hint of blue, so it lets Empire Grey hold its depth while keeping things from feeling heavy. On a deep colour like this, a properly bright warm white on the woodwork stops the room closing in.
For a tonal partner, Mylands Beehive Place No.140 (LRV 58.6) sits in the same family — a warm, honeyed neutral that brings light to a room without breaking the warm mood. Use it on an adjoining wall, in a hallway running off the main room, or on the upper half of a wall above a panelled section painted in Empire Grey.
For accents, this is where you have fun. A deep oxblood like Dulux Fuchsia Falls 2 (LRV 29.8) gives you that rich, slightly decadent contrast that flatters smoky greens beautifully — think a feature door, an alcove, or soft furnishings. For something moodier and more masculine, Paint & Paper Library Blue Blood (LRV 16.4) brings a properly dark, inky depth that grounds the scheme.
The "but what about" question I always get: *should I add another green?* You can, but you don't need to — Empire Grey already does the green-grey work. Better to layer texture instead. Limed oak flooring or furniture, unlacquered brass hardware that'll patina over time, and a bit of warm timber all do more for this colour than a second green ever will.
Practical tip: test it large and live with it across the day. Empire Grey shifts noticeably between bright daylight and lamplight — gorgeous and atmospheric by evening, more grey by morning. North-facing rooms will read it cooler, so warm up the lighting if needed.