Testing large paint samples around 24 by 24 inches provides a more accurate view of how paint colors interact with your room’s lighting, floors, and trim. Small swatches often mislead because they don’t show undertones clearly or how colors shift in natural light. Large samples eliminate visual noise from surrounding colors, revealing true color behavior under daylight and artificial bulbs. This approach helps you avoid costly repainting and ensures you select a color you’ll confidently love.