Usually that would indicate an infection, however if there are no accompanying symptoms (swelling, discharge, odour, etc) then it could be minor enough that the body's white cells are healing it. I would still recommend putting a bandage and a medicated ointment on it however - if there is any infection in the wound, it will be obvious on the worn bandage's cotton gauze pad (ie. yellowing on the pad). The pad and ointment should effectively draw any infection out of the wound.