A beautiful, vibrant color on the walls of a room can turn disappointingly dull as the day gets longer. With every passing hour, color becomes more and more “shaded” or “toned,” which diminishes the natural vitality of the original hue. What is more, walls, windows, and refl ections from fl ooring, furnishings and other heavy objects in a space all work together at any time of day to “dull out” your color.In her many years of working with homes of all shapes and sizes, decorating guru, Alexandra Stoddard, of Alexandra Stoddard Inc. in New York City, has become an expert on light and its effects -- not only on color -- but the soul as well. She recommends using white -- the purest white possible -- as your indoor equivalent of the sun. She maintains that when you add white to the natural, original, clear colors you choose, you will experience a pleasant rainbow effect that feeds the spirit instead of depriving it. White affects the relationship and placement of a room’s color scheme, so not only will it help them remain cheerful as the sun goes down (or behind the clouds), but there will be a sense of peace and symmetry between them. One color will not fight another. Given that philosophy, Ms. Stoddard always advises to “tint up” rather than down, when choosing room colors, which simply means adding more pure white to the original color. You don’t have to go “pastel,” which is another word for heavily tinted, but you should go lighter than what you probably have in mind.And be sure to do the “artificial light test,” when shopping with your paint chips or swatches. Carry a mini-flashlight or tiny reading light and shine it directly on the color. This will give you an idea of how the color will look in your room at night, illuminated by artificial light. The trick of the matter is, your colors should look delicious at all times. For more information about lighting, in general, please see our special section on LIGHTING, this page.