See if the colored paper has stuck and dried on the tabletop. If so, loosen it with a solution of 1-part vinegar to 2 parts warm water mixed in a bowl. Dip a sponge in the solution and rub gently over the paper until it comes off the table and the surface is clean.
Sand the entire tabletop with fine-grit sandpaper to remove the top layers of stained wood. Work in long, smooth strokes with the grain, paying particular attention to the stained area. Continue sanding until you no longer see the stain.
Wipe the entire tabletop with a soft cloth dampened with mineral spirits. The mineral spirits will deep-clean the surface, removing wood particles and any remaining stain from the colored paper.
Dip the corner of a piece of cheesecloth in the wood stain and wipe it on the surface. Use smooth strokes, covering the table quickly and uniformly. Allow it to dry for several hours then sand with fine-grit sandpaper and apply a second coat of stain. Let it dry overnight.
Paint the tabletop with at least one coat of polyurethane with a paintbrush, sanding lightly between coats and allowing four to five hours between coats. The polyurethane will seal and protect the wood against future stains from colored paper.