Is one allowed to use a toilet deodorizer that colors the water on shabbos?
It is very common nowadays to put a deodorizer inside the bowl of the toilet, so that when the toilet is flushed, the water runs over the deodorizer, and makes a pleasant smell in the bathroom. The poskim discuss the fact that very often the deodorizer is colored, and in turn dyes the water in the toilet. Therefore many poskim say that the deodorizers without any color are permitted, however the ones with a color should not be used, and should be removed before Shabbos.
If one wants to use a toilet bowl disinfectant that is colored, he may put it into the tank of the toilet, and this is permissible, even though it will color the water. If the deodorizer was not removed from the toilet before shabbos, and the use of this toilet, (as well as the need for the toilet to be flushed) are needed, the deodorizer may be removed. This is because the need to use and flush the toilet involve כבוד הבריאות-human dignity, and one may move מוקצה for כבוד הבריות. Note; if the deodorizer can be removed with ones body i.e. ones foot, or with another object, such as a rod etc., that is preferred.
Shmiras Shabbos K’hilchoso 23-14 ftnt. 44 frm R’ S. Z. Auerbach zt”l, MInchas Shlomo 2-14, Shavet Halvei 8-176, Orchos Shabbos 7 ftnt. 8, 15-64, ftnt.94, Be’er Moshe 8-22,23,