So, I just noticed a really odd discrepancy between my front rotors and the swept area (evidenced on the rotor) of the pads. I replaced the worn OEM discs/pads for the AP Racing 2-piece J Hooks and Hawk Ceramic pads (HB905Z.646) in January and this is the first time I am noticing the issue - see photos below. What's also odd is that the outer portion of the rotor face (about 3/4") does have concentric marks, as if the entirety of the face is in contact with the rotor. But, I cannot explain the obvious discoloration in the photos. Any ideas?