Is there any leniency in the ruling regarding water becoming impure if its color changes slightly or moderately while retaining its form, due to the hardship involved?

If an object that comes into contact with water is pure, then the water does not become impure by its contact, nor does it lose its purifying quality, unless its color changes significantly. However, if the change is slight, it does not lose its purifying quality. But if water changes due to an impurity, then it becomes impure, whether the change is slight or extensive. One must beware of obsessive doubts. If there is doubt about water mixing with an impurity, this doubt is not to be considered unless there is certain conviction.