Eucalyptus is one of those quiet, dusky grey-greens that does a lot of heavy lifting in a room without ever shouting. The trick with it is warmth — it's got just enough grey in the base that the wrong partner can drag it flat and lifeless.
The boldest move, and the one I'd push you towards, is to drench the whole room — walls and woodwork in Eucalyptus together. Skirting, architrave, the lot. It looks expensive and considered, and it stops the green from reading as a wishy-washy feature wall.
If you want contrast on your trim, go for a warm off-white — never brilliant white. Brilliant white turns Eucalyptus grey and joyless. Paper III from Paint & Paper Library (LRV 75.3) is a lovely creamy partner, and Farrow & Ball Au Lait (LRV 80) is even softer and warmer — both keep that green looking gentle rather than cold.
For grounding — a sense of weight at floor level or on built-in furniture — Mylands Cigar BH.20 (LRV 11.8) is a rich, smoky brown that echoes old oak and antique brass beautifully. It gives the scheme somewhere to land.
And for the bit of life that stops a green room feeling static, reach for faded plum and dusty rose. Dulux Fuchsia Falls 2 (LRV 29.8) is a muted, dusky pink that sits opposite Eucalyptus on the wheel — perfect for cushions, a chair, or a single accent wall in a bedroom.
The but-what-about: "can I do metals?" Yes — antique brass and aged gold, every time. Chrome and bright nickel will fight it. Keep your hardware and lighting warm-toned and the whole thing pulls together.
Practical tip: paint A2-sized boards and look at them morning and evening, because Eucalyptus shifts more than most greens with the light. North-facing rooms make it cooler and more grey — lean harder on the warm off-whites there.