If yellowness is observed after performing ghusl and standing on a prayer rug, is the entire body and the rug considered impure, or only the site of impurity, given that the body is wet?

If the yellowish discharge is a fluid that exits a woman's private parts, it is impure (najis) and necessitates Wudu' if it appears after purification. However, if it is connected to menstruation, it takes the ruling of menstruation. The ruling of impurity is limited to the area it afflicts, and that area must be purified.