To create the illusion of width in a room that is longer than it is wide, which color should be used on the short walls?

The use of warm colors on the short walls of a room that is longer than it is wide is effective for creating the illusion of width. Warm colors, such as reds, oranges, and yellows, tend to be more stimulating and can help to visually 'pull' the walls closer together. This gives the sensation of a more inviting and spacious area, optimizing the perception of the room's dimensions.

By painting the short walls with warm colors, it contrasts with the longer walls, which may typically be painted in cooler or more neutral tones. This technique draws the eye across the short walls and creates a balanced visual perception of the space, making it feel less elongated and more proportionate. In contrast, other options might not provide the same dimensional effect, potentially leaving the length of the room more pronounced.