For future references if someone is looking, that bluing is normal for the stainless material. The SRT-4 runs pretty high exhaust temps (up to 1720°F pre-turbine) and run rich at wide-open throttle to aid exhaust cooling but that can temporarily increase catalyst temps. The common three-way catalytic converters on gasoline powered vehicles require around an 800°F internal operating temp.
Had you wanted to test it, you would have needed to do a pressure check with it on the car. Testing can be done by temporarily removing the upstream and downstream O2 sensors, install an adapter fitting and length of copper tubing (to provide cooling) and an accurate low-pressure range gauge on the end of the copper tubing. If you have a DRB-III or newer scan tool Chrysler's official test involves installing a pressure sensor in place of the upstream (pre cat) O2 sensor and idling the car at 2k rpms. The back pressure should be no more than 3.45 Kpa (0.5 psi).
Eric H. - '04 Neon SRT-4 (eBlue/S2) - '04 SRT-4 (blk/stock & now sold)
'92 Dodge Daytona IROC R/T --
'91 Dodge Spirit R/T
plus a couple other turbo Dodges, a Cobalt, a couple Focus, big S/C wagon, and some other stuff...