It may be due to the light changing the colour of the exposed floor rather than a stain - answer is the same though. If the floor is plastic laminate and the change in colour is due to light then I don't see many options. If it is wood it may be possible to refinish by stripping/sanding etc but it depends on the thickness of any veneer - thin veneer cannot be sanded for obvious reasons. Good Luck
Ant, November 2007
Usually once laminate is stained, there's no removing. You cannot strip laminate, try a flooring place they might have better advice.