Are you talking about the pads on the fibers. they are black from heat. Probably someone thrashing them or using improper oil. I must admit they are not mine. just pictures someone I was helping sent me for evaluation. Here is a shot of the OEM new on the right compared to the MTC fibers which I use and much prefer on the left.
My 07 has the OEM ones something else I would have changed while I was in her if I was not 1000 miles from home. Thank god I had a trailer to pull her apart and fix her.