I've had the same issue with my malibu cloth interior, being the grey color it seemed to even stain from water spilling on it. What I have found is that when you take a wet/damp terry cloth and dub the entire seat so that it gets slightly damp then go over it with a dry cloth when the entire area dries it is clean and with out the water looking stain you described.
So pretty much you have to dampen and dry the entire area everytime a small spill happens.
Hope this helps
