Many people are shocked when an area rug is moved and there is an outline of the rug on the floor. Luckily there is no need to panic. If you remove the rug completely the colour will blend eventually but it will take a while, so be patient. This happens because the sunlight causes the floor to discolour but as it does not reach the floor under the rug this remains unaffected. This discolouration can be avoided by moving the rugs often or by using a finish with a UV block on it.