We just recently had a sunroom built onto the back of our house. When they laid the tile there were a lot of divots in the grout. The tile guy came back and patched the divots by putting more grout in those spots. Well now the patched spots are a different color than the original grout. Now the manufacturer of the grout says they have a stain to fix this and want us to let them stain all the grout. Does anything here seem odd? I am not at all comfortable with them staining the grout. Please advise.