New Walther PPS .40 (rust?)

[gtmtnbiker98]

Just bought a new toy, a Walther PPS chambered in .40 S&W. During my initial cleaning, I noticed some orange colored discoloration in the joints adjacent to the locking block and areas just forward of the locking block. I swear that this looks like rust, but doesn't quite look like rust. Any ideas of what this could be?

I've looked over at Walther Forums and noticed a brief discussion; however, nobody seemed to have a definitive answer. Has any other owners of the PPS .40 noticed this discoloration?

TIA