Instead of painting all four walls the same color, paint or finish just one — usually the wall behind a bed's headboard or a sofa, wherever the eye naturally lands — in a bolder color, pattern or material, letting that single wall act as the room's anchor.
Which wall gets picked matters. The wall facing the entrance, or the one that long-stay furniture like a bed or sofa backs onto, is usually the safest choice. A wall with a window is often skipped, since a bold finish there tends to block light.
An accent wall only works if the other three stay neutral. Give another wall a strong color or pattern too and the room now has competing focal points — once one wall is chosen as the accent, the rule is to keep everything else restrained.
When to use
Use it to add impact to an all-white room without much cost. Prioritize the wall a bed or sofa backs onto, or the one facing the entrance, and skip a wall with a window.