The trick with a low ceiling is to stop the eye finding a hard line where wall meets ceiling. A crisp, contrasting white ceiling against a darker wall actually shouts "here's the boundary" — which is the last thing you want.
Keep the ceiling lighter, but soft. A bright brilliant white can feel cold and flat, drawing attention to itself. Go for a gentle off-white instead — Farrow & Ball Wevet or Slipper Satin up top reads as light without that stark, attention-grabbing glare. Little Greene Loft White is another lovely ceiling tone that recedes nicely.
Blur the join. The single most effective move is to bring the ceiling colour down onto the cornice (if you've got one) and even the top 6–10 inches of wall. With no sharp horizontal line, your eye keeps travelling upward and the room feels taller. Painting the cornice the same as the ceiling — never a contrast — is non-negotiable for low rooms.
Pale, receding walls help too. Cool, light tones recede and make walls feel further away. Cornforth White or Skimming Stone are soft greys that hold a wall without closing it in. Avoid heavy, saturated colours below picture-rail height if you're truly tight on height.
Now the "but what about" — *should I paint the ceiling the SAME as the walls?* For a genuinely poky room, yes, this works brilliantly. Wrapping one continuous light colour over walls and ceiling removes every boundary and the room feels like a balloon expanding. Strong White or Wevet wrapped right round is a designer's classic for low cottage ceilings.
One more thing: vertical lines and tall, narrow elements (full-height curtains hung close to the ceiling, vertical panelling) reinforce the height illusion. And go matt on the ceiling — flat, chalky finishes hide unevenness and don't bounce light back at you the way a sheen does.
Keep it light, keep it soft, and lose that hard line.