Adding warmth without painting is doable by focusing on warm lighting and repeated accent colors. Switch all bulbs to warm 2700 kelvin light and layer lighting sources like lamps and uplights. Incorporate one accent color such as rust, sage, or teal through textiles, plant pots, and artwork repeated at least three times. Add textured materials like linen or velvet to rugs and throws. These steps deliver warmth, depth, and coziness without changing the walls.