A study is the one room where you can go properly deep without second-guessing it. This palette puts a moody deep forest on the walls, the kind of green that reads almost black in a dark corner and softens to pine when the desk lamp comes on. It wraps the room and quiets it down, which is exactly what you want when you are trying to think.
To keep that green from feeling heavy, I surround it with warmth. Warm linen on the built-ins and a cleaner soft chalk on the trim and ceiling give the eye somewhere bright to rest, while a walnut brown desk and shelving ground the scheme in real wood tones. The browns and the green belong together, like a forest floor.
The one spark is burnished brick — a warm, earthy red I would use on a single accent: a reading chair, a strip of shelf backing, or the inside of a cabinet. Keep it to one small surface. Used on more than a corner of the room it fights the calm instead of lifting it.