The pilot lost control of the recently painted helicopter during the takeoff. The paint shop personnel had moved the helo to an airplane parking spot. The helo skids straddled the tie-down chains. Two wing tie-down chains were incorrectly attached to the right landing gear skid. One witness indicated that he walked around the helo examining the new paint before the arrival of the pilot and passengers. He stated that he did not notice any tie-down chains on the aircraft. The pilot did not notice the tie-down chains during the preflight check and did not remove them. The chains were attached without tension. As the helo came to a hover, the slack was taken up. With the right skid tube tethered, the helo rolled right allowing the main rotor blades to strike the ground. AC 20-35C states, 'Fasten the tie-down ropes to the fuselage mooring points and extend them to the ground mooring anchors'. The chains were dark brown in color and did not clearly contrast with the asphalt surface.