Does water become impure if it becomes turbid or shallow due to impurity, while retaining its color and form as water?

If an impurity falls into water and changes its color, even slightly, the water is considered impure and cannot be used for purification (tahara). However, if the water does not change, then: if it is less than two Qullas (160.5 liters), it is considered impure according to the majority of scholars; but if it is more than two Qullas, it does not become impure unless it changes. According to the Maliki school, water does not become impure merely by the admixture of an impurity unless one of its characteristics changes.