Before using any throw rugs on your floor you should know the type of finish you have on your floor.
All rugs should be non-staining, meaning the colored dyes will not bleed thru. Generally in the presence of moisture, some dyes used in rugs may bleed through onto your floor and discolor the wood floors surface. Also, be sure the rug does not have a rough backing material that may scratch the surface of the floor. Clean dirt and debris from under the rug regularly. To prevent possible shading of the wood underneath the rug, move the rug occasionally.