Explorer ST Borla Exaust installed

[Forddealz]

For those that purchased the Borla Exhaust with the black chrome tips, have you noticed any discoloration as of late?

I have had Borla for almost 2 weeks now and I am very satisfied. This is how the ST should come from factory because the stock one's had almost no sound. I do not see any discolorations on the black tips and also no tiny rocks attaching to the tips.