Toilet set in plaster of paris

[Imovemetal]

Hello to all and thanks in advance for your reply. Just a quick question. Recently had a toilet set and the plumber used plaster of paris to aid. A week later the plaster around the base of the toilet is starting to change color from the white to a brownish color. There is no visible moisture on the floor. I'm assuming that this color change is due to a leak under there somewhere. Is this correct? Thanks again

 

[phishfood]

It could be a leak. It also could be color seeping from wooden shims, if he used them to steady the toilet when he set it in place.