Are you sure you have the OEM version? I know there are very cheaply made replicas being sold on eBay. I've never heard of the letters separating from the tape. You mean the 3M tape is sticking to the car and the letters are coming off? I've never heard of or seen that. The emblems we'll be getting are exact replicas made of the same ABS plastic as the OEM version and using automotive grade 3M double sided tape.
The closest thing I have to black right now is carbon fiber:
OEM Kia Stinger Badge Chrome or Carbon Fiber - KIA STINGER DOT COM
It's dark. I WILL be receiving glossy black, matte black, black chrome and a few other colors...