Air carrier First Officer reported while taxing into the gate they felt like they struck something and stopped the aircraft. The flight crew believe they struck a catering truck that was behind the red line.

Narrative

I was the FO (First Officer) on flight XXXX Day 0 ; ZZZ1-ZZZ.After a short hold off the ramp awaiting our gate we were cleared to gate. As we taxied into the gate I verified and said the area was clear as all vehicles/items were behind the red line. We taxied in at a very slow speed and about 20 feet or so from the jet bridge it felt like we struck something.I looked ahead and to the right and didn't see anything. At that point the CA (Captain) said he thought we struck a catering truck that was behind a red line on the left side of the plane.The aircraft was stopped ;and a PA was made to remain seated. After clearance from ground personnel was received the plane was taxied to the gate. The Chief Pilot was contacted and a maintenance entry was completed.Night time ; inadequate ramp lighting.The ramp safety zone markings (red) are not easily distinguished from the fire line" (red) markings from the cockpit at night with less than ideal ramp lighting - especially if the area in question does not have safety zone markings ."