EMB-145 First Officer reported that confusion over MEL procedures resulted in the aircraft operating with both thrust reversers being locked out.

Narrative

I was scheduled to fly from ZZZ to ZZZ1 with Captain. Before the flight we discussed MEL and I verified that the E2 thrust reverser locking pin was in place; but due to a lack of clarity with the MEL; Aircraft X may have flown with both thrust reversers locked. Upon arrival in ZZZ1 I was scheduled to fly a ZZZ2 turn with Captain in the same aircraft. After doing the post flight walk around; I questioned Captain about both thrust reversers being locked and after reviewing the MEL he explained to me that at least one thrust reverser is required for dispatch so we then notified Maintenance Control and Operations.Due to lack of experience with MELs; and the inconspicuous color of the thrust reverser locking pins; Aircraft X may have flown with both thrust reversers locked even though the MEL states that one thrust reverser is required for dispatch.Despite discussing the MEL and the locking pins with both Captains; the thrust reverser locking pins that were installed on the aircraft were recessed from outer surface of the engine and were an inconspicuous color of a plain bolt or pin. Based on my training; I expected the thrust reverse locking pins to be a high visibility color such as red or yellow; however they were not. The incorrect configuration of the aircraft may have been noticed before we flew the aircraft if the thrust reverser locking pins were a highly conspicuous color.