ATS Coupe Wheels??? WHY NO 19 INCH OPTION LIKE SEDANS

I am getting the run around from the Cadillac dealers on this. If someone has a coupe out there and tried the really nice 19 inch split 5 spoke OEM Cadillac wheels please let me know. I don't understand why they would not fit. I talked to one Cadillac dealer and they told me only the black 19 inch wheels would fit my car. Why the hell would the wheel color make a difference??? I have a feeling the sedan and the coupe offsets are the same for the staggered sets. I am just not sure. Is there anyone out there who can help me.

I have a 2015 ATS Coupe with 18X8 front and 18X9 rear and would like to know if the sedan 19 inchers will work...