Adulting is exactly what it says on the tin — a proper, considered blue with a cool undertone that wants careful company. The cleverest move is to drench the room: walls and woodwork in the same colour for the most resolved, enveloping result. That's how this colour looks best, full stop.
If you want a ceiling break, go warm but never stark. Farrow & Ball Au Lait (LRV 80) is a lovely soft milky white that takes the chill off without going yellow, and Paper III from Paint & Paper Library (LRV 75.3) does the same job with a touch more depth. Both keep the room feeling calm rather than clinical — a brilliant white overhead would fight the blue and make it look harsh.
For contrast and grounding, Mylands Cigar BH.20 (LRV 11.8) is your hero. It's a deep, brooding brown that anchors Adulting beautifully — think skirting, a feature joinery run, or a piece of furniture. The blue-against-brown combination reads expensive and very grown-up.
Want a bit of life? A measured hit of Dulux Fuchsia Falls 2 (LRV 29.8) brings warmth and personality — a single panel, the inside of a cupboard, or soft furnishings. Used sparingly it stops the scheme tipping into cold.
The one rule you can't break: avoid yellow brass. It fights the blue undertone every time and looks dodgy. Go for blackened steel handles, taps and lighting instead, and bring in pale oak for flooring or furniture — the lighter wood keeps things fresh rather than heavy.
My practical advice: drench first, then add Au Lait or Paper III above if the room feels low, ground with Cigar, and keep the Fuchsia as a whisper. Sample big, look at it morning and evening — blues shift more than most.