Almost every interior textile (carpet, rugs, upholstery, draperies and wall coverings) will lighten in color or fade over a period of time. The extent of damage depends on the item's location, exposure to light and elements, color, intensity and type of dyes, and the dyeing method used.
An interior textile that has been solution-dyed (or producer colored) is least susceptible to sunlight fading. The pigments are added to the polymer before the fibers are formed, sealing in the color. Most olefins (polypropylene and polyethylene), many acrylics, and some polyester and nylon fibers used in carpet are dyed using this method.
Lighter shades usually will fade more quickly than darker shades because they contain less dye. Most dyes are composed of two or more color components. If one color is affected more than the other, the fading may appear as a color change rather than a lightening of the color. For example, many greenish hues are made from yellow and blue dyes. If the yellow dye is affected and the blue is not, the green textile may seem to be turning blue. To confirm this process for yourself, visit a museum and examine antique tapestries with trees and grass. These green colors now appear very blue because the yellow dye has faded.
In other instances, colors may fade uniformly, appearing as a lighter shade of the original color. In severe cases, the color may be completely removed, appearing to be "bleached" white. The fiber itself may also deteriorate. This is especially problematic with silk textiles.
You may be able to prevent interior textiles from fading in sunny locations by keeping the windows covered with draperies (which may fade, too) or by treating the windows with a protective coating that filters out the ultra-violet (UV) rays of sunlight. If you live in an area where sunlight fading is a problem, shop carefully for all interior textiles.