The answer to 'upholstery discolored' is that there are several common causes, including sun exposure, spills or stains, and general wear and tear over time. Symptoms may include fading, yellowing, or other color changes in the fabric. The best solution depends on the cause and severity of the discoloration.
For minor discoloration, you may be able to DIY with a fabric cleaning solution or mild soap and water. However, for more significant or stubborn discoloration, it's best to call in a professional upholstery cleaning service. They have the right tools and expertise to safely and effectively restore the color and condition of your upholstery without causing further damage.