It is caused by various factors, including under the color of the rug, which means that it is unscheduled and decoded: 1) the lack of cream and its color. Lack of skills and accuracy in cream color. 3D of cream during the carpet. (4) Uncorrect exploitation of rugs and drags it uniformly in a place that has different light and sun: this defect usually appears after a little time of operation, and if the rug has enough talent, it will be resolved