Where an occupant of real estate has color of title thereto, and in good faith has made valuable improvements thereon, and is afterwards in a proper action found not to be the owner, no execution shall issue to put the owner in possession of the same after the filing of an action as hereinafter provided, until the provisions of this act have been complied with; provided said occupant may elect, after filing of the action, to exercise his right to remove such improvements if it can be done without injury otherwise to such real estate.