Paint colors for small or dark rooms

Two strategies work in a small or dark room, and they point in opposite directions. Either maximize the light you have with warm, reflective near-whites like cream, ivory, and pale putty, or stop fighting and go deliberately deep, letting a saturated color turn the room into a cocoon. What fails is the middle ground: mid-tone beiges and grays that neither bounce light nor commit to mood.
The light-maximizing route
Cool bright whites are the default advice and the common regret: without strong daylight they turn gray and clinical. In a dark room, choose whites with a warm base (cream, soft ivory, mushroom), which return lamp light as glow instead of glare. Keep the ceiling the same color or one shade lighter. A sharp white ceiling above warm walls draws a line that lowers the room.
Sheen matters more here than in bright rooms. An eggshell finish reflects meaningfully more light than dead-flat matte, without the shine of satin.
The cocoon route
Deep green, aubergine, or ink blue painted on every wall, trim included, makes a small room feel intentional instead of insufficient. The trick is total commitment. Wrapping the whole envelope removes the contrast lines that reveal how close the walls are. Add warm bulbs and brass or wood accents; a dark room with good lamps beats a pale room with bad ones every evening of the winter.
Preview both before you choose a side
This is the rare decision where candidates differ so much that imagination fails. Render both on a photo of the actual room, the cream version and the deep green version in the same light, same furniture. Repaint applies each scheme to your photo in about a minute, and the comparison usually ends the debate on the spot. One of the two will obviously belong to your room.

Questions
Does painting the ceiling the wall color make a room feel smaller?
In small rooms it usually does the opposite: removing the wall-to-ceiling contrast line blurs the box’s edges. Sharp white ceilings emphasize exactly where the room ends.
What sheen hides wall imperfections in a dark room?
Matte hides bumps best but absorbs light; eggshell is the working compromise in dark rooms, noticeably more reflective, still forgiving.