Ok i've screwed up I admit it !!!!

:'(Today I was cleaning a rug on what looked like a limestone floor, I was careful to wipe up any over spray as i went along the edge. but too my horror when i moved the rug the stone was alot lighter round the rug where i had overspray and really does stand out, in cleaning sollution i was using crystal Green from prochem.
I would be grateful for any advice.