Most species of hardwood change color to some degree over time. This change, known as patina or aging, is mostly caused by exposure to sunlight. As a result, any flooring covered by furniture or rugs will not darken as quickly as exposed areas. If you rearrange the furniture, rest assured that the previously covered areas will catch up in a few months. To slow the patina process, hang directional blinds in your windows and aim the sunlight toward the ceiling. This also helps prevent upholstery and wall paint from fading over the years.