Improper or defective dyes inherent in manufacturing. A defective dye is one that has not been properly selected or properly applied.
Dyes are sensitive to pH and temperatures when being applied.
Colors like brown, gray, and black are made of primary hues like yellow, red, and blue. If yellow, red, and blue are not closely matched with respect to pH and temperature, then bleeding or crocking will likely occur with either usage or maintenance. The cushion below is made of Cheneille and has experienced dye bleeding after cleaning. Note the dark areas. A Blowup of the yarn of the cut sample reveals that yellow and not black has actually bled indicating that yellow dyes were improperly selected or applied.