Discolored refers to an object that has undergone a change in color, usually due to natural aging or exposure to environmental factors. Synonyms for discolored include dingy, faded, stained, yellowed, sullied, muddied, tarnished, and grimy. Dingy implies a dull, dirty appearance, while faded suggests a loss of brightness over time. Stained refers to a surface that has been marked by a substance, while yellowed means that the color has turned yellow. Sullied and tarnished both suggest a loss of purity or shine, while muddied refers to an object that has been covered in dirt or mud. Grimy indicates a surface covered in dirty marks or soot.