Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 240; Flight Crew Type 10000
Distraction; Time Pressure; Situational Awareness
Inflight Event / Encounter Other / Unknown
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Airport
Runway 11 at AUA has the visual illusion of a vehicle on the runway at midfield.  As we passed through 1;000 feet on final approach to AUA; the Pilot Flying said to me 'I think that there might be a vehicle on the runway'. I could immediately observe a dark; vehicle-sized object clearly contrasted on the concrete runway surface in the first third of the runway. I asked Tower to verify a clear runway. The Tower Controller complied and offered that we were cleared to perform a go-around; if we deemed that to be necessary.  As we got within 200 feet of touchdown; I focused hard and could discern that it was; in fact; a patch of asphalt (or paint) on the concrete surface. As we entered the flare; it was totally obviously NOT a vehicle or any threatening object.
B737-700 Captain reported a visual illusion on the runway due to discolored asphalt.