Start with Prussian Blue, a deep ink-and-ocean blue that sets a calm, grown-up mood the moment it goes up. It reads almost like a soft black from across the room, but up close it stays clearly blue, which gives a space that quiet, lived-in richness without feeling cold. It is the kind of color that makes everything in front of it look a little more considered.
Then comes the warmth. Golden Mustard is the spark that keeps all that depth from going gloomy, glowing against the blue like lamplight and giving the whole scheme its vintage, collected feel. Soft Stone is the breather between them, a warm putty neutral that softens the trim and the edges so the contrast never feels harsh. Lean on the blue for the main surfaces, let the stone carry the trim, and save the mustard for the pieces you want people to notice. It is an easy combination to carry across a living room, a bedroom, a kitchen, or a whole connected home.