Those with a high or low pH can discolor and pit the floor´s surface Here's one site I found.

I have a rowhouse with crumbly, discolored and just ugly concrete floor.

Murphy loves to come visit, like my almost rent ready rental that had a roof leak yesterday...fortunately it was minor and just discolored the paint so it's a quick cheap fix...but that's not always the case.

There is limited discoloration in areas. 

I think part of the problem may be minerals (rust) in the water that discolors it. 

The slight discoloration due to mold does not seem to be toxic , especially since I applied mold control liquids and bleach.

Also discoloration of the paint. 

It removes discoloration - and nothing more.

NOTE:  bleach/water combo will only wash away the surface discoloration. 

Urine stains usually remain as discoloration.