Anyone know about OEM pads?

[SugrueNSX]

I just bought a new set of OEM pads and I notice that the rear pad material is different from the front. The back is a light brown and the front is nearly black.
Anyone know if this is normal? Why do they do this?

Thanks,

Patrick

 

[Shumdit]

It is possible that since the fronts do far more of the braking they use a harder material for the front? Possibly organic rear pads and carbon metallic fronts?